Leading up to the final two rubbers of this year’s Davis Cup final in Croatia, the hosts were heavily favored. They held a 2-1 advantage, and both of the remaining singles matches would pit a Croatian against a lower-ranked Argentine. To win the Cup, they only needed to win one of those matches.
When Marin Cilic built a two-set lead over Juan Martin del Potro, Croatian fans could be forgiven for thinking it was in the bag. Instead, Delpo fought back to win in five sets, and Federico Delbonis upset a flat Ivo Karlovic to seal Argentina’s first-ever Davis Cup title. Some people will point to the Cilic-Delpo match time of 4:53 as another reason to switch to best-of-three. The rest of us will see it as yet another reminder of why best-of-five must retain its role on tennis’s biggest stages.
In a best-of-three format, Cilic would’ve claimed the Cup for Croatia after two hours of play. Instead, he merely came very close. My Elo singles ratings gave Cilic a 36.3% chance of beating Delpo and Karlovic a 75.8% chance of defeating Delbonis. Taken together, that’s a likelihood of 84.6% that Croatia would claim the trophy. After Cilic won the first two sets, his odds increased to about 81%, pushing Croatia’s chances over the 95% mark. In fourteen previous tries, del Potro had never recovered from an 0-2 deficit.
And then Argentina came back. Comebacks from two sets down tend to stick in our memory, so it’s easy to forget just how rare they are. Yesterday’s match was only the 28th such comeback in 2016. That’s out of a pool of 656 best-of-five contests, including 431 in which one player built a 2-0 lead. This year isn’t unusual: Going back to 2000, the number of wins from a 0-2 deficit has never exceeded 32.
Comebacks from 0-2 are even rarer in Davis Cup. At the World Group level this year, including play-offs, Delpo was the 61st player to fall into a 0-2 hole, but he was only the second to recover and win the match. The other was Jack Sock, whose July comeback (over Cilic–more on that in a bit) wasn’t enough to move his USA squad into the semifinals. Since 2000, 5.8% of 2-0 leads turn into comeback victories, but only 4.3% of World Group 2-0 leads do the same.
Cilic’s season has defied the numbers. In addition to his 2-0 collapses against Sock and del Potro, he held a 2-0 advantage before losing to Roger Federer in the Wimbledon quarterfinals. His 2016 is only the third time in ATP history that a player lost three or more matches after winning the first two sets. The previous two–Viktor Troicki’s 2015 season and Jan Siemerink’s 1997–are unlikely to make Cilic feel any better.
Still, even Cilic’s record indicates the rarity of victories from an 0-2 disadvantage. Before the Wimbledon quarterfinal, the Croatian had never lost a match after taking the first two sets, for a record of 60-0. Even now, his Davis Cup record after going up two sets to love is a respectable 11-2. His overall career mark of 95.7% (66-3) is better than average.
Unless Cilic crumbles under certain spotlights (but not others, as evidenced by his five-set win over Delbonis on Friday), his series of unfortunate collapses may just be a fluke. In addition to that 60-0 streak, he has never had a problem converting one-set leads in best-of-three matches. This year, he won 29 out of 33 best-of-threes after winning the first set, an above-average rate of 88%. (And one of the losses was against Dominic Thiem, so he never had a chance.)
The longer the match format, the more likely that the better player emerges triumphant. That’s why there are fewer upsets in best-of-five than in best-of-three, and why tiebreaks are often little better than flips of a coin. Usually that works in favor of a top-tenner such as Cilic: In most matchups he is the superior player. But in two of his three collapses this season, he’s fallen victim to a favorite who uses the longer format to overcome an early run of poor form.
The debate over best-of-five will surely continue, despite this weekend’s Davis Cup tie adding another unforgettable five-set epic to an already long list. But after Delpo’s performance yesterday, you’ll have a harder time finding someone to campaign for shorter matches–especially in Argentina.