Wimbledon is currently the only Grand Slam in tennis that actively departs from the official tour rankings when it seeds players. On the WTA, it is done by a committee, and is therefore more subjective, but on the ATP, there's a clear defined formula. The calculation is done for the top 32 players on the ATP rankings - so anyone who was supposed to be seeded, will be - but not necessarily according to his usual ranking.
The formula works this way:
- Take the ATP ranking points at 17 June 2013 (a week before the tournament starts)
- Add 100% points earned for all grass court tournaments in the past 12 months - that includes s'Hertogenbosch/Eastbourne 2012, Newport 2012, Wimbledon 2012, Olympics 2012, Queen's/Halle 2013.
- Add 75% points earned for the best grass court tournament in the 12 months before that (One of s'Hertogenbosch/Eastbourne 2011, Wimbledon 2011, Newport 2011, Queen's/Halle 2012).
Based on that, we can already calculate the possible scenarios for the Wimbledon 2013 seedings. The scenarios are actually quite simple, though the calculations aren't, so we'll start from the conclusions:
Wimbledon 2013 seedings:
#2 Andy Murray
#4 David Ferrer
#5 Rafael Nadal
If you want to check my calculations, you can read ahead.
Andy Murray & Roger Federer
This calculation is a bit easier, since we already know their Roland Garros results.
Murray currently has 8670 points, and since he didn't play in the French Open, he'll lose his QF points from last year, and will have 8310 points this Monday. Ignoring Queen's 2013 for a second, he'll add 1950 points from the previous 12 months (Wimbledon final and Olympics title). His best result from the 12 months before that is 720 points from the 2011 Wimbledon semifinal, so he'll add 540 more points for that, bringing us to a total of 10800 points. His 2013 Queen's result will be added to that total twice - once as a part of the regular rankings, and once in the "last 12 months" category, so 10800 is the absolute minimum he can get.
Federer has 8000 points. He'll lose the 720 RG 2012 SF points, and will add 360 points for this year's QF, for a total of 7640 points this Monday. Without Halle 2013, his previous 12 months' points are 2450 (Wimbledon title and Olympics final). He'll also add 75% * 360 points for his 2011 Wimbledon QF. As for Halle: On June 17, he'll drop 150 points from the final of Halle 2012, and add whatever he earns in Halle 2013, twice. Even if he wins Halle (thus adding a total of 2*250=500 points), this will bring his total points (for seeding purposes) to 10710 - not enough to overtake Murray in any scenario.
David Ferrer & Rafael Nadal
If Nadal wins RG, he'll have 6895 points on Monday (just like his current points, since he's defending the title). Halle 2012 is already non countable for him, so he doesn't drop any more points. At the moment, he only has 45 points in that category, for his R2 in Wimbledon 2012. He gets 75% * 1200 = 900 points for the 2011 Wimbledon final. Overall, this gets him to 7840 points.
Ferrer, in this scenario, will have 7220 points this Monday (current points - 6740, drops 720 for 2012 RG SF, adds 1200 for 2013 RG F). He never plays in Queen's or Halle, so we know exactly that his last 12 months' points are 680 (Wimbledon QF, Olympics R16, s'Hertogenbosch title), and he adds 75% * 180 = 135 points for 2011 Wimbledon R16. Thus, his total points for seeding purposes will be 8035 - ahead of Nadal.
Clearly, if Ferrer wins RG, the gap between his and Nadal's points will be even larger, and he'll be seeded #4 (even an RG win won't be enough to bump him to #3 right now).
By the way, if Nadal did play Halle, he'd have to win both RG and Halle to be seeded #4.
June 19 edit: The official seedings for Wimbledon 2013 (both men and women, singles and doubles) can be found on the Wimbledon website.
June 19 edit: The official seedings for Wimbledon 2013 (both men and women, singles and doubles) can be found on the Wimbledon website.