Dominic Thiem played Davis Cup in Barcelona. Sort of…

This is a guest post by Peter Wetz.

Last week Dominic Thiem fought his way into the finals of the Barcelona Open by winning against Kyle Edmund, Daniel Evans, Yuichi Sugita, and Andy Murray. Three of these four players play for the same flag and Thiem won against each of them. Thiem is not exactly a champion of the current Davis Cup format–he has opted out of playing for Austria several times and has a rather poor record of 2-3 when he does compete–but in Barcelona he has, at least, shown that he can beat several players from the same country over a short amount of time. And that’s what Davis Cup is about, right?

In this post my goal is to put this statistical hiccup into some context. It is not the first time the Austrian defeated three players of the same nationality at one event: In 2016 at Buenos Aires Thiem already beat three players from Spain. However, given that Spanish players appear much more frequently in draws than Britons do, I will take a closer look.

Since 1990, there have only been three tournaments where a single player faced three players from Great Britain. And only one of these players who faced three Britons won each encounter. The following table shows the three tournaments and each of the matches where a player from Great Britain was faced by the same player. Wally Masur is the only player since 1990 who defeated three players from Great Britain in a single tournament. Thiem remains the only player who achieved this in a tournament outside of the island.

Tournament     Round Winner        Loser           Score
'93 Manchester R32   Wally Masur   Ross Matheson   6-4 6-4
'93 Manchester R16   Wally Masur   Chris Wilkinson 6-3 6-7(4) 6-3
'93 Manchester QF    Wally Masur   Jeremy Bates    6-4 6-3

'97 Nottingham R32   Karol Kucera  Martin Lee      6-1 6-1
'97 Nottingham SF    Karol Kucera  Tim Henman      6-4 2-6 6-4
'97 Nottingham F     Greg Rusedski Karol Kucera    6-4 7-5

'01 Nottingham R32   Martin Lee    Lee Childs      6-4 5-7 6-0
'01 Nottingham R16   Martin Lee    Arvind Parmar   6-4 6-3
'01 Nottingham QF    Greg Rusedski Martin Lee      6-3 6-2

Obviously, there are not many chances to face three Britons in a single tournament. And when one of those opponents is likely to be Andy Murray, a player’s chances of beating all three are even slimmer.

Let’s broaden the perspective a bit and take a look at how often a player defeated three (or more) players from the same country without looking only at Great Britain. The following table displays the results of this analysis. The first column contains the country, the second column (3W) shows how often a player defeated three players of this country, the third column (3WL) shows how often a player defeated two players of this country and then lost to a player of the same country, and so on.

Country  3W  3WL  4W  4WL  5W  5WL
USA      119 179  19  30   1   4
ESP      98  157  17  18   3   2
FRA      28  45   5   2    1   0
ARG      22  26   5   3    0   0
GER      15  18   1   1    0   0
AUS      13  9    0   0    0   0
SWE      9   16   1   0    0   0
CZE      4   5    0   0    0   0
NED      4   4    0   0    0   0
RUS      4   3    0   0    0   0
ITA      2   3    1   0    0   0
BRA      1   3    1   0    0   0
GBR      1   2    0   0    0   0
CHI      1   1    0   0    0   0
SUI      1   1    0   0    0   0

As we could have imagined, USA, ESP, and FRA come out on top here, simply, because for years they have had the highest density of players in the rankings. These are also the only countries of which a player was faced five times at a single tournament. Facing a player of the same country six or more times never happened according to the data at hand. The following table shows the most recent occasions of the entries printed in bold in the above table (5W).

Tournament    Round Winner        Loser             Score
'91 Charlotte R32   Jaime Yzaga   Chris Garner      7-6 6-3
'91 Charlotte R16   Jaime Yzaga   Jimmy Brown       6-4 6-4
'91 Charlotte QF    Jaime Yzaga   Michael Chang     7-6 6-1
'91 Charlotte SF    Jaime Yzaga   M. Washington     7-5 6-2
'91 Charlotte F     Jaime Yzaga   Jimmy Arias       6-3 7-5
'07 Lyon      R32   Sebastien Gr. Rodolphe Cadart   6-3 6-2
'07 Lyon      R16   Sebastien Gr. Fabrice Santoro   4-6 6-1 6-2
'07 Lyon      QF    Sebastien Gr. Julien Benneteau  6-7 6-2 7-6
'07 Lyon      SF    Sebastien Gr. Jo Tsonga         6-1 6-2
'07 Lyon      F     Sebastien Gr. Marc Gicquel      7-6 6-4
'08 Valencia  R32   David Ferrer  Ivan Navarro      6-3 6-4
'08 Valencia  R16   David Ferrer  Pablo Andujar     6-3 6-4
'08 Valencia  QF    David Ferrer  Fernando Verdasco 6-3 1-6 7-5
'08 Valencia  SF    David Ferrer  Tommy Robredo     2-6 6-2 6-3
'08 Valencia  F     David Ferrer  Nicolas Almagro   4-6 6-2 7-6

Finally, we take a look at the big four. Did they ever eliminate three or more players from the same country in a single tournament? Yes, they did. In 2014 Roger Federer beat three Czech players in Dubai. In 2005, 2008, and 2013 he beat three German players in Halle. In 2009 Andy Murray beat three Spanish players in Valencia. In 2007 Novak Djokovic beat three Spanish players in Estoril. In 2013 Rafael Nadal beat three Argentinian players both in Acapulco and Sao Paolo. In 2015 he even beat four Argentinian players in Buenos Aires. And there are many other examples where Rafa beat three of his countrymen at the same tournament.

We can see that this happens fairly often, specifically for countries where the tournament is organized, because more players of this country appear in the draw due to wild cards and qualifications. If we exclude these cases, Federer’s streak in Dubai stands out, as does Thiem’s streak in Barcelona.

Peter Wetz is a computer scientist interested in racket sports and data analytics based in Vienna, Austria.

Dominic Thiem and the Best Deciding-Sets Seasons in ATP History

Yesterday at the ATP World Tour Finals, Dominic Thiem won a three-set match against Gael Monfils, his 22nd deciding-set victory of 2016. Despite losing to Novak Djokovic in three sets on Sunday, Thiem is enjoying one of the best deciding-set seasons in ATP history.

The loss to Djokovic was only Thiem’s third in 25 deciding sets this year. He began the season with 14 consecutive deciding-set wins, including back-to-back third-set tiebreaks in Buenos Aires against Rafael Nadal and Nicolas Almagro. He strung together another seven straight between May and September, including a grass-court upset of Roger Federer in Stuttgart.

Among players who contested at least 20 deciding sets in a season, Thiem’s winning percentage of 88% is the fifth-best record in the ATP’s modern era. Not every player reaches the 20-decider threshold–some, like Djokovic, avoid it by winning most of their matches in straight sets–but it’s no statistical oddity. There have been nearly 1,000 player-seasons with at least 20 deciders since the 1970s, including Andy Murray’s 17-6 record in 2016.

Outstanding single-season deciding-set records don’t guarantee long-term success. Thiem appears on this list amid a mix of famous and lesser-known names, from Federer to Onny Parun:

Player           Year  Deciders  Wins  Win Perc  
Mario Ancic      2006        24    22     91.7%  
Ilie Nastase     1971        23    21     91.3%  
Tom Okker        1974        20    18     90.0%  
Roger Federer    2006        20    18     90.0%  
Dominic Thiem    2016        25    22     88.0%  
Kei Nishikori    2014        24    21     87.5%  
Stan Smith       1972        22    19     86.4%  
Joakim Nystrom   1984        22    19     86.4%  
Guillermo Vilas  1977        29    25     86.2%  
Onny Parun       1975        34    29     85.3%

Parun’s 1975 season is particularly notable, as no other player has won so many deciding sets in a single year. In 1996, Yevgeny Kafelnikov came close, winning 28. One gets the idea he was trying: He played 105 matches that year, 40 of which went the distance. In more recent years, big names have played more limited schedules, and Thiem is the only active player to win at least 22 deciding sets in a single season. Dmitry Tursunov gave it a shot in 2006, playing 37 deciders, but he won only 20.

Like so many tennis stats, this one can be fluky. For every Kei Nishikori–who has won an incredible 77% of deciding sets at tour level, including some record-setting streaks--there is a Grigor Dimitrov, who won 18 of 22 deciding sets in 2014, then barely broke even the following year, claiming only 11 of 21. Of the 27 players who have posted a 20-decider, 80% winning percentage season, not a single one managed an 80% winning percentage the following year.

For all of his talents, Thiem probably won’t follow in Nishikori’s footsteps. The Austrian won only half of his 40 deciding sets before this season. But a more modest record in these matches is hardly insurmountable. In 1996, Pete Sampras put together his best deciding-sets record, winning 83% of his 24 deciders. The following year, his record fell to a pedestrian 56%, which didn’t keep him from winning two Grand Slams and finishing the season at the top of the rankings.

If Thiem is to continue climbing the rankings, he’ll be better off taking Djokovic’s path, winning most of his deciding sets, but playing them much less frequently. In the last decade, Novak has played 20 deciding sets in a season only three times, and he has only gone the distance 10 times in 2016. Even Nishikori would have to agree: Djokovic’s method is working just fine.

Elina Svitolina and Multiple #1 Upsets

Last week in Beijing, Elina Svitolina beat new WTA #1 Angelique Kerber. It was the first time the Ukrainian defeated Kerber this season, but it wasn’t her first 2016 triumph over a player ranked #1. At the Rio Olympics in August, Svitolina upset then-top-ranked Serena Williams.

It’s unusual for a player to face two (or more) different #1-ranked opponents in the same season. Since 1985, it has happened 136 times on the WTA tour and 148 times on the ATP tour. That’s less than five times per season per tour.

Of course, it’s much less common to upset multiple #1-ranked opponents, as Svitolina did. This was only the 16th time a woman did so (again, since 1985), while it has happened on the men’s side 18 times.

Here is a full list of WTA player-seasons that featured defeats of more than one top-ranked player:

Year  Player               Upsets                      
2016  Elina Svitolina      Kerber; Serena              
2010  Samantha Stosur      Serena; Wozniacki           
2009  Venus Williams       Serena; Safina              
2008  Dinara Safina        Henin; Sharapova; Jankovic  
2006  Justine Henin        Davenport; Mauresmo         
2003  Justine Henin        Serena; Clijsters           
2002  Kim Clijsters        Serena; Venus               
2002  Serena Williams      Capriati; Venus             
2001  Lindsay Davenport    Capriati; Hingis            
1999  Amelie Mauresmo      Hingis; Davenport           
1999  Venus Williams       Davenport; Hingis           
1997  Amanda Coetzer       Hingis; Graf                
1996  Jana Novotna         Graf; Seles                 
1996  Kimiko Date Krumm    Graf; Seles                 
1991  Martina Navratilova  Graf; Seles                 
1991  Gabriela Sabatini    Graf; Seles

It’s quite an accomplished list. As we might expect, there’s a lot of overlap between the players who achieved these upsets and past and future #1-ranked players. The real standouts here are Justine Henin and Venus Williams, who managed the feat twice, and Dinara Safina, who faced three different #1s in 2008, going undefeated against them.

Here are the men who beat multiple #1s in the same season:

Year  Player                 Upsets             
2013  Juan Martin Del Potro  Nadal; Djokovic    
2012  Andy Murray            Federer; Djokovic  
2011  David Ferrer           Nadal; Djokovic    
2011  Jo Wilfried Tsonga     Nadal; Djokovic    
2010  Marcos Baghdatis       Nadal; Federer     
2009  Juan Martin Del Potro  Nadal; Federer     
2008  Andy Murray            Nadal; Federer     
2008  Gilles Simon           Nadal; Federer     
2003  Rainer Schuettler      Roddick; Agassi    
2003  Fernando Gonzalez      Hewitt; Agassi     
2001  Greg Rusedski          Safin; Kuerten     
2001  Max Mirnyi             Safin; Kuerten     
1995  Michael Chang          Agassi; Sampras    
1992  Richard Krajicek       Courier; Edberg    
1991  Guy Forget             Edberg; Becker     
1991  Andrei Cherkasov       Edberg; Becker     
1990  Boris Becker           Lendl; Edberg      
1988  Boris Becker           Wilander; Lendl

This list isn’t quite as impressive, though it does capture several very good players at their best.  It also highlights the world-beating potential of Max Mirnyi, who–despite never reaching the top 15 himself–finished the 2001 season with a 3-1 record against ATP #1s.

The rarity of facing multiple #1s in the same season–let alone beating them–stops us from drawing any meaningful conclusions about what Svitolina’s feat indicates for her future. At the very least, however, it reminds us of the Ukrainian’s potential as a future star, and puts her among some very good historical company.

Andrey Kuznetsov and Career Highs of ATP Non-Semifinalists

When following this week’s ATP 250 tournament in Winston-Salem and seeing Andrey Kuznetsov in the quarterfinals the following question arose: Will he finally make it into the first ATP semifinal of his career? As shown here Andrey – with a ranking of 42 – is currently (by far) the best-ranked player who has not reached an ATP SF. And it looks as if he will stay on top of this list for some time longer after losing to Pablo Carreno Busta 4-6 3-6 on Wednesday.

With stats of 0-10 in ATP quarterfinals, he is still pretty far away from Teymuraz Gabashvili‘s streak of 0-16. Despite having lost six more quarterfinals before winning his first QF this January against a retiring Bernard Tomic, Teymuraz climbed only to a ranking of 50. Still, we could argue that the QF losing-streak of Teymuraz is not really over after having won against a possibly injured player.

Running the numbers can answer questions such as “Who could climb up highest in the rankings without having won an ATP quarterfinal?” Doing so will put Andrey’s number 42 into perspective and will possibly reveal some other statistical trivia.

Player                Rank            Date   On
Andrei Chesnokov        30      1986.11.03    1
Yen Hsun Lu             33      2010.11.01    1
Nick Kyrgios            34      2015.04.06    1
Adrian Voinea           36      1996.04.15    1
Paul Haarhuis           36      1990.07.09    1
Jaime Yzaga             40      1986.03.03    1
Antonio Zugarelli       41      1973.08.23    1
Bernard Tomic           41      2011.11.07    1
Omar Camporese          41      1989.10.09    1
Wayne Ferreira          41      1991.12.02    1
Andrey Kuznetsov        42      2016.08.22    0
David Goffin            42      2012.10.29    1
Mischa Zverev           45      2009.06.08    1
Alexandr Dolgopolov     46      2010.06.07    1
Andrew Sznajder         46      1989.09.25    1
Lukas Rosol             46      2013.04.08    1
Ulf Stenlund            46      1986.07.07    1
Dominic Thiem           47      2014.07.21    1
Janko Tipsarevic        47      2007.07.16    1
Paul Annacone           47      1985.04.08    1
Renzo Furlan            47      1991.06.17    1
Mike Fishbach           47      1978.01.16    0
Oscar Hernandez         48      2007.10.08    1
Ronald Agenor           48      1985.11.25    1
Gary Donnelly           48      1986.11.10    0
Francisco Gonzalez      49      1978.07.12    1
Paolo Lorenzi           49      2013.03.04    1
Boris Becker            50      1985.05.06    1
Brett Steven            50      1993.02.15    1
Dominik Hrbaty          50      1997.05.19    1
Mike Leach              50      1985.02.18    1
Patrik Kuhnen           50      1988.08.01    1
Teymuraz Gabashvili     50      2015.07.20    1
Blaine Willenborg       50      1984.09.10    0

The table shows career highs (up until #50) for players before they won their first ATP QF. A 0 in the last column indicates that the player can still climb up in this table, because he did not win a QF, yet. There may also be retired players being denoted with a 0, because they never managed to get past a QF during their career.

I wonder, who had Andrei Chesnokov on the radar for this? Before winning his first ATP QF he pushed his ranking as far as 30. He later went on to have a career high of 9. Nick Kyrgios could also improve his ranking quickly without the need to go as deep as a SF. His Wimbledon 2014 QF, Roland Garros 2015 R32, and Australian Open 2015 QF runs helped him to get up until #34 without a single win at an ATP QF. Also, I particularly would like to highlight Alexandr Dolgopolov who reached #46 before having even played a single QF.

Looking only at players who are still active and able to up their ranking without an ATP SF we get the following picture:

Player                 Rank            Date
Andrey Kuznetsov         42      2016.08.22
Rui Machado              59      2011.10.03
Tatsuma Ito              60      2012.10.22
Matthew Ebden            61      2012.10.01
Kenny De Schepper        62      2014.04.07
Pere Riba                65      2011.05.16
Tim Smyczek              68      2015.04.06
Blaz Kavcic              68      2012.08.06
Alejandro Gonzalez       70      2014.06.09

Andrey seems to be relatively alone with Rui Machado being second in the list having reached his highest ranking already about five years ago. Skimming through the remainder of the table, we would be surprised if anyone soon would be able to come close to Andrey’s 42, which doesn’t mean that a sudden unexpected streak of an upcoming player would render this scenario impossible.

So what practical implications does this give us for analyzing tennis? Hardly any, I am afraid. Still, we can infer that it is possible to get well within the top-50 without winning more than two matches at a single tournament over a duration that can even range over a player’s whole career. Of course it would be interesting to see how long such players can stay in these ranking areas, guaranteeing direct acceptance into ATP tournaments and, hence, a more or less regular income from R32, R16, and QF prize money. Moreover, as the case of 2015-ish Nick Kyrgios shows, the question arises how one’s ranking points are composed: Performing well at the big stage of Masters or Grand Slams can be enough for a decent ranking while showing poor performance at ATP 250s. On the other hand, are there players whose ATP points breakdown reveals that they are willing to go for easier points at ATP 250s while never having deep runs at Masters or Grand Slams? These are questions which I would like to answer in a future post.

Peter Wetz is a computer scientist interested in racket sports and data analytics based in Vienna, Austria. I would like to thank Jeff for being open-minded and allowing me to post these surface-scratching lines here.

Teymuraz Gabashvili and ATP Quarterfinal Losing Streaks

Yesterday in Moscow, Teymuraz Gabashvili played his 16th career tour-level quarterfinal. Facing 118th-ranked Evgeny Donskoy, it was his best chance yet to reach an ATP semifinal, but just as in each of his previous 15 attempts, he lost.

No other player has contested so many tour-level quarterfinals without ever winning one. But while the streak of 16 consecutive quarterfinal losses is a rarity, it’s not a record. The all-time mark belongs to Gianluca Pozzi, who dropped 18 in a row between 1993 and 2000. Pozzi’s record, depressing as that streak is, might be an inspiration to Gabashvili: At age 35, Pozzi finally broke the streak, defeating Marat Safin, one of the best players he ever faced in a quarterfinal.

Gabashvili and Pozzi are among only twelve players who have strung together more than 10 quarterfinal losses at tour level. Here’s the complete list, including the dates of the first and last loss in each streak:

Player               QFs L Streak     Start       End  
Gianluca Pozzi                 18  19930104  20000501  
Teymuraz Gabashvili            16  20070219         *  
Paul Annacone                  14  19860127  19880704  
Ivan Molina                    12  19751110  19791105  
Mischa Zverev                  11  20060925  20090713  
Diego Perez                    11  19861124  19920810  
Anand Amritraj                 11  19750304  19810706  
Dennis Ralston                 11  19701101  19800602  
Bob Carmichael                 11  19720918  19751231  
Ricardas Berankis              10  20120917         *  
Yen Hsun Lu                    10  20070219  20130923  
Mikhail Youzhny                10  20041101  20060130

Ricardas Berankis is the only other player on this list to have an active streak, and since he’s five years younger than Gabashvili, another few years of mild success and quarterfinal futility could put him in the running for the all-time record. Alas, neither player is likely to repeat the post-streak success of Mikhail Youzhny, who went on to play 63 more tour-level quarterfinals, winning 33 of them.

If there’s a silver lining for Gabashvili, it’s that he’s reached all of those quarterfinals, sparing himself the fate of Rolf Thung, a Dutch player from the 1970s who reached the round of 16 at 18 tour events and lost them all.

Benoit Paire and Overqualified Challenger Contenders

With three ATP tour-level events on the slate this week, Benoit Paire considered his options and elected to play none of them. Instead, the world #23 is the top seed at the Brest Challenger, making him the highest ranked player to enter a challenger this year–by a wide margin.

Top-50 players may only enter challengers if they are given a wild card, and top-ten players may not enter them at all. Still, since 1990, a top-50 player has played a challenger just over 500 times, at a rate of about 20 per year. (Some of these players didn’t need a wild card, as entry is determined by ranking several weeks before the tournament, during which time rankings rise and fall.)

Many of the high-ranked wild cards fall into one of two categories: Players who lose early in Slams, Indian Wells, or Miami; and clay-court specialists seeking more matches on dirt. Paire’s decision this week–like the Frenchman himself–doesn’t follow one of these common patterns.

Anyway, here are the top-ranked players to contest challengers since 1990, along with their results. A result of “W” means that the player won the title, while any other result indicates the round in which the player lost.

Year  Event           Player               Rank  Result  
2003  Braunschweig    Rainer Schuettler    8     R16     
1991  Johannesburg    Petr Korda           9     SF      
1994  Barcelona       Alberto Berasategui  10    W       
1994  Graz            Alberto Berasategui  11    R16     
2008  Sunrise         Fernando Gonzalez    12    QF      
2004  Luxembourg      Joachim Johansson    12    W       
2011  Prostejov       Mikhail Youzhny      13    QF      
2008  Prostejov       Tomas Berdych        13    QF      
2003  Prague          Sjeng Schalken       13    W       
2005  Zagreb          Ivan Ljubicic        14    W       
2004  Bratislava      Dominik Hrbaty       14    F       
2004  Prostejov       Jiri Novak           14    QF      
2003  Prostejov       Jiri Novak           14    R32     
2007  Dnepropetrovsk  Guillermo Canas      15    SF      
2002  Prostejov       Jiri Novak           15    F       
1998  Segovia         Alberto Berasategui  15    QF      
1997  Braunschweig    Felix Mantilla       15    F       
1997  Zagreb          Alberto Berasategui  15    W

(Schuettler and Korda were outside the top ten a couple of weeks before their respective challengers.)

A look at this list suggests that Alberto Berasategui entered challengers as a top-fifty player more than anyone else. He’s close–with 12 such entries, he’s tied for second with Jordi Arrese. The player who dropped down a level the most times is Dominik Hrbaty, who played 17 challengers while ranked in the top 50. (The active leaders are Jarkko Nieminen with ten and Andreas Seppi with nine.)

Despite all those attempts, Hrbaty wasn’t particularly successful as a high-ranked challenger player. He won only 2 of those 17 events, reaching only one other final. Top-50 players aren’t guaranteed to win these titles, of course, but in general, they have outperformed Hrbaty, winning 18% of possible titles. Here are top-50 players’ results broken down by round:

Result       Frequency  
Title            18.1%  
Loss in F         9.3%  
Loss in SF       11.3%  
Loss in QF       17.1%  
Loss in R16      22.0%  
Loss in R32      22.2%

Paire is a better player than this sample’s average ranking of 37. Combined with a favorable surface, he gets a much more optimistic forecast from my algorithm, with a slightly better than one-in-three chance of winning the title. With a futures title, an ATP trophy, and a pair of challenger triumphs already in the books this year, it seems fitting that Benoit would add another oddity to his wide-ranging season.

Continue reading Benoit Paire and Overqualified Challenger Contenders

Lucky Losers and Familiar Faces

In the final round of qualifying Monday in Moscow, Darya Kasatkina easily defeated Paula Kania. Thanks to a couple of late withdrawals, both players ended up making the main draw … and tomorrow, they’ll play each other again.

This scenario is rare, but not unheard of. Since the mid-1990s, there have been 30 other instances when two women faced each other in qualifying and then again in the main draw. Most recently, Lauren Davis defeated Svetlana Kuznetsova twice at the 2013 Canadian Open. One year earlier, in Sydney, Alexandra Dulgheru beat Sofia Arvidsson in the first round of the main draw despite losing to her in the final round of qualifying.

Tomorrow’s Kasatkina-Kania rematch is far from a sure thing. In those 30 prior matches, barely more than half of the qualifiers–17 of 30–have managed to win both matches.

This sort of rematch is similarly uncommon on the ATP tour. Since 2007 (the earliest year for which I have qualifying results), this has happened a dozen times. Most recently, Albert Ramos-Vinolas defeated Robin Haase in back-to-back rounds in Monte Carlo. Ramos was on the opposite side of things five years ago, when Pablo Cuevas beat him twice in Valencia.

Earlier this year, in a variation on the theme in Auckland, Kenny de Schepper beat Alejandro Falla to qualify, and after both players won their first-round matches, Falla triumphed in the second-round rematch.

Programming note: After watching this sort of ad hoc research disappear into the barely-searchable void that is the Twitter archive, it occurred to me to post occasional brief notes such as this one. It’s not groundbreaking stuff, but at least it’ll be easier to find in the future. These curiosities won’t interfere with or replace my longer, more analytical posts.