{"id":3768,"date":"2019-11-13T16:24:09","date_gmt":"2019-11-13T16:24:09","guid":{"rendered":"http:\/\/www.tennisabstract.com\/blog\/?p=3768"},"modified":"2019-11-13T16:24:09","modified_gmt":"2019-11-13T16:24:09","slug":"tramlines-and-wide-groundstrokes","status":"publish","type":"post","link":"https:\/\/www.tennisabstract.com\/blog\/2019\/11\/13\/tramlines-and-wide-groundstrokes\/","title":{"rendered":"Tramlines and Wide Groundstrokes"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">The NextGen Finals are played on an unusual court, in that the surface is marked only for singles matches, leaving out the &#8220;tramlines&#8221; that define the doubles alleys. Virtually all tennis events includes doubles, as well, so this is rarely an option. The ATP has skipped tramlines at season-ending events before, but at the end of the 2010s, the singles-only court is exclusive to the NextGen Finals.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One might reasonably wonder whether the unique paint job has any effect on play:<\/p>\n\n\n\n<figure class=\"wp-block-embed-twitter wp-block-embed is-type-rich is-provider-twitter\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"twitter-tweet\" data-width=\"550\" data-dnt=\"true\"><p lang=\"en\" dir=\"ltr\">I\u2019d be fascinated to know if less balls go \u2018wide\u2019 on a court without trams. Does it focus the mind more? \ud83e\udd14<\/p>&mdash; Lisa (@furryyelloballs) <a href=\"https:\/\/twitter.com\/furryyelloballs\/status\/1192168870133583877?ref_src=twsrc%5Etfw\">November 6, 2019<\/a><\/blockquote><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script>\n<\/div><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">I discussed this on a <a href=\"http:\/\/www.tennisabstract.com\/blog\/2019\/11\/10\/podcast-episode-77-erik-jonsson-on-swedish-tennis-and-the-nextgen-finals\/\">recent podcast with Erik Jonsson<\/a>, and we tentatively concluded that tennis pros (even young ones) with thousands of hours of playing experience shouldn&#8217;t be affected by a tweak to the appearance of the court. But why speculate when we can look at some data?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"http:\/\/www.tennisabstract.com\/charting\/meta.html\">Match Charting Project<\/a>, my volunteer-driven effort to log shot-by-shot records of professional tennis matches, notes various details about errors&#8211;forced or unforced, and &#8220;type&#8221;&#8211;net, deep, wide, or wide-and-deep. MCP contributors didn&#8217;t immediately take to the NextGen Finals&#8211;before this week, the 2018 final was the only charted match out of the 6,600 matches in the dataset&#8211;but 2019 was different. We now have shot-by-shot stats for 8 of the 15 matches played in Milan last week. (Big thanks to <a href=\"http:\/\/www.tennisabstract.com\/charting\/matches_Carrie.html\">Carrie<\/a>, who took charge of <a href=\"http:\/\/www.tennisabstract.com\/cgi-bin\/player.cgi?p=AlexDeMinaur\" target=\"_blank\" rel=\"noopener noreferrer\">Alex de Minaur<\/a>\u2019s entire run to the final.)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Quantifying wide errors<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We&#8217;re interested in the frequency of wide errors, which isn&#8217;t quite as simple as it sounds. I chose to focus only groundstrokes, and I also excluded forced errors&#8211;shots on which the player might not have much control of the direction of the ball.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Here are three metrics we could use for the frequency of wide errors:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Wide errors per point<\/li><li>Wide errors per unforced error<\/li><li>Wide errors per &#8220;makeable&#8221; groundstroke&#8211;that is, groundstrokes that were either unforced errors or put in play<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Wide errors per point is probably too crude, but it does have the advantage of simplicity.  Wide errors per unforced error might have some value, telling us in what direction a player was most aggressive.  The last, wide errors per makeable groundstroke, is probably the best representation of what we&#8217;re looking for, as it tells us how frequently a player tried to hit a shot and it went wide.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Here are de Minaur&#8217;s numbers for his five 2019 NextGen matches, along with his hard-court aggregates from 28 other charted matches in the last two years:<\/p>\n\n\n\n<pre>          Wide \/ Pt  Wide \/ UFE  Wide \/ GS  \nNextGen        2.7%        1.5%      21.7%  \nATP Hard       3.0%        1.4%      21.4%<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">At least for Alex, the tramlines don&#8217;t seem to make much of a difference.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let&#8217;s look at the slightly larger group of players. We have eight matches, which means 16 records of one match for a single player, including at least one for each of the eight guys who qualified for Milan. Here are the three wide-error rates for the NextGen Finals matches, along with the same players&#8217; wide-error rates for other charted hard court matches in the last two years:<\/p>\n\n\n\n<pre>          Wide \/ Pt  Wide \/ UFE  Wide \/ GS  \nNextGen        3.2%        1.8%      19.5%  \nATP Hard       3.2%        1.8%      23.1%<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">For our first two metrics, there is absolutely no effect. Tramlines or no tramlines, wide errors mark the end of 3.2% of points, and 1.8% of total unforced errors. (The 3.2% figure is <em>per player<\/em>, meaning that 6.4% of points were ended with a wide error.)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The third metric, though, is more interesting. On tour, these players make a wide error on 23.1% of their &#8220;makeable&#8221; groundstrokes. That number dropped by more than one-seventh, to 19.5%, on the tramline-free court in Milan. At the same time, the overall rate of unforced errors (not just wide errors) <em>increased<\/em> compared to the same players&#8217; efforts on hard courts at other events.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Deep mind<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I see two possible explanations for such a substantial drop. First, we don&#8217;t have much data, and maybe it&#8217;s just a fluke of a small sample. Some of the difference can be traced to <a href=\"http:\/\/www.tennisabstract.com\/cgi-bin\/player.cgi?p=UgoHumbert\" target=\"_blank\" rel=\"noopener noreferrer\">Ugo Humbert<\/a>, who didn&#8217;t make a single wide error in his one charted NextGen Finals match. (Humbert&#8217;s usual wide-error rates are close to average.) Without a lot more matches played on tramline-free surfaces&#8211;not to mention charts of those matches&#8211;we won&#8217;t be able to draw a firm conclusion.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Second, it could be a real effect stemming from some aspect of the conditions in Milan. The lack of tramlines really might, as Lisa puts it, &#8220;focus the mind.&#8221;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Compared to other innovations trialed at the NextGen Finals, the singles-only court gets very little press. But unlike, say, the towel rack or the <a href=\"http:\/\/www.tennisabstract.com\/blog\/2018\/09\/19\/the-effect-of-the-us-open-serve-clock\/\">shot clock<\/a>, it might just have a small effect on play.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The NextGen Finals are played on an unusual court, in that the surface is marked only for singles matches, leaving out the &#8220;tramlines&#8221; that define the doubles alleys. Virtually all tennis events includes doubles, as well, so this is rarely an option. The ATP has skipped tramlines at season-ending events before, but at the end &hellip; <a href=\"https:\/\/www.tennisabstract.com\/blog\/2019\/11\/13\/tramlines-and-wide-groundstrokes\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Tramlines and Wide Groundstrokes<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[46,65,106],"tags":[],"class_list":["post-3768","post","type-post","status-publish","format-standard","hentry","category-groundstrokes","category-match-charting","category-shot-by-shot-stats"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/posts\/3768","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/comments?post=3768"}],"version-history":[{"count":0,"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/posts\/3768\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/media?parent=3768"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/categories?post=3768"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tennisabstract.com\/blog\/wp-json\/wp\/v2\/tags?post=3768"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}