Through the first four rounds at Wimbledon, Roger Federer‘s serve has not been broken. In that span, he has faced nine break points, including only four in his last three matches.
Since 1991–the first year for which match stats are available–this is only the 8th time a player reached the quarters of a men’s major without losing serve. Only Federer in 2004 and Ivo Karlovic in 2009 have done so at Wimbledon. Federer and Nadal are the only players to have done so more than once. (Fed was also unbroken through four matches in Melbourne last year, and Rafa accomplished the feat at the 2010 and 2013 US Opens.)
Roger’s nine break points faced are a bit less impressive. More than 5% of the 752 Grand Slam quarterfinalists since 1991 have allowed fewer, including Federer himself on several occasions. He allowed only three break points at Wimbledon in 2007, and only four at three other majors.
Dominant as such a performance is, it’s less clear whether it has any predictive value. A major confounding factor is quality of competition–would anyone expect Paolo Lorenzi or Santiago Giraldo to break Federer on grass? While he built on these superb serving performances and went on to win the title at Wimbledon in 2004 and 2007, he failed to do so at the three majors when he allowed only four break points through this stage of the tournament.
Without accounting for player quality, there is a weak negative correlation between matches won at the event and break points (and breaks) allowed. (For instance, for matches won and break points allowed in the first four matches, r = -0.25. Excluding Roland Garros, r = -0.27.) In other words, if all you know about two players is how many break points they faced in the first four rounds, bet on the guy who faced fewer.
But it’s a weak relationship, and when player quality is taken into account, it vanishes to almost nothing. Eight of the 24 players who were broken one or fewer times in the first four rounds went on to win the title, but I suspect that has more to do with the prevalence of Rafa, Roger, and Pete Sampras–the best players are most likely to go unbroken, and the best players are most likely to go deepest at Slams.
When the best players struggle on serve in early rounds, it’s hardly a death knell for their title chances. Only four times in Fed’s 31 previous hard- and grass-court Slam quarterfinal runs has he been broken more than six times before the quarters, and he won the tournament one two of those four occasions. He’s surely happy to be into the quarterfinals this week with a minimum of fuss, but the fuss level only says so much about how happy he’ll be come Sunday.