It’s a fair assumption to make - that a top quality performer will perform better in sets four and five in Grand Slams, as opposed to in set three of an ATP match. After all, one of the primary reasons for a top player being highly ranked is because they are fitter, and have better support teams (nutritionists, coaches, physios, etc) than their lowly rivals, who simply cannot afford such luxuries.
When first considering how to approach this, I initially wanted to look at Wimbledon in isolation, given that it is the current Grand Slam on the calendar, but upon closer examination, it became apparent that sample size was more of an issue when focusing on one Slam only. In addition, perhaps it’s fair to suggest that Wimbledon is less of a test of fitness than the other three Grand Slams, which are typically played in hotter conditions, and with longer points - points on grass tend to be of shorter duration than other surfaces, particularly clay.
What did Twitter think?
Certainly the masses on Twitter were convinced of this assumption. I ran a poll on twitter and over 60% of respondents voted that a top 20 player would have a better record in a deciding fifth set, as opposed to a deciding third set, with the voting between a worse record in a deciding fifth set, and around the same figures, being quite evenly split.
Interested in getting some thoughts on whether you think that the combined top 20 record in a deciding 5th set should be better/worse than their record in deciding 3rd sets - for a future article with @Cloudbet ...
— Dan Weston (@Tennisratings) July 10, 2018
While it is easy to dismiss this as a simple Twitter poll, it’s worth noting that many of those taking the time to vote will comprise a proportion of the tennis betting markets, given that my follower count is vastly biased towards those users.
In fact, the majority was incorrect. I assessed the current world top 20 (rankings prior to Wimbledon) and also included Novak Djokovic and Andy Murray, who have consistently been at that ranking level prior to long-term injuries.
From 2015, onwards this ‘top 22’ won 56.29% of fourth sets in Grand Slams (66.02% when 2-1 up prior to the fourth set, and 42.54% when 1-2 down prior to the fourth set), a figure which rose to 59.06% for deciding fifth set wins. This 59.06% for fifth set victories was very marginally higher than the 58.49% for deciding third set wins in non-Slam ATP matches.
So, we can see that these ‘top 22’ players won just 0.57% more deciding fifth sets than deciding third sets, but trying to ascertain a logical reason for there being little split is quite difficult. On the surface, it would appear that top players have little edge over the field in terms of additional ability in very long matches.
Why does this happen?
Perhaps the most logical explanation is that when they play a deciding fifth set, the score in sets is 2-2, so the opponent of the high-ranked player has won two sets. While this is 50% of the sets available, the same as at 1-1 in a best of three set match, it is a lot easier for a lower ranked player to nick one set and get to 1-1 in a best of three, than two sets and get to 2-2 in a best of five.
Therefore, for a higher ranked player to get to 2-2 in a best of five set match, they’d be relatively likely to be struggling in the match already, or their opponent is playing to something close to their peak level - as opposed to a higher variance spot at 1-1 in a best of three.
It’s like a snooker match - it’s much easier for a lowly player to win five sets in a best of nine frame match in a small event than it is to win 18 in the best of 35 frames in the World Championship Final.
Essentially, the shorter the time-frame of a match, the more likely there is to be a surprise result.
As with virtually all assessments of betting strategy, historical results indicate that a blind-backed strategy is a poor choice. A number of players had excellent records in late stages of matches, including Juan Martin Del Potro (won 72.73% of 4th/5th sets combined in Slams, and 67.86% of 3rd sets in standard ATP events), as well as Dominic Thiem (68.75%, 67.14%), David Goffin (70.97%, 63.51%), Novak Djokovic (68.97%, 75.68%), and Andy Murray (69.23%, 72.22%).
Those who performed relatively poorly in longer matches in the time frame assessed included Marin Cilic (57.14%, 51.72%), Grigor Dimitrov (40.74%, 54.43%), John Isner (53.85%, 53.13%), Diego Schwartzman (45.45%, 44.68%) and Sam Querrey (40.00%, 45.61%) - these players look like the ones you wouldn’t want to take into battle during a long match, if playing the in-play markets.