Wimbledon uses seeding which gives advantage to players that are more successful on grass courts. (Although I am not sure how long have they used seeding in this way.)
For example, in Wikipedia article on 2014 Wimbledon Championships we can read that:
The Gentlemen's singles seeds is arranged on a surface-based system to reflect more accurately the individual player's grass court achievement as per the following formula, which applies to the top 32 players, according to ATP Ranking on 17 June 2013:
- Take Entry System Position (ESP) points at 16 June 2014
- Add 100% points earned for all grass court tournaments in the past 12 months (16.06.2013 – 15.06.2014).
- Add 75% points earned for best grass court tournament in the 12 months before that (12.06.2012 – 15.06.2013)
For the Ladies' singles seeds, the seeding order follows the ranking list, except where in the opinion of the Committee, the grass court credentials of a particular player necessitates a change in the interest of achieving a balanced draw.
Are there some other tournaments which do not follow ATP/WTA rankings? In general, can organizers of a tournament make changes to seeding, if they want to do so?