Based on the provided statistics for Kempton from the last 5 years, there are a few potentially profitable betting angles and trends.

Firstly, looking at the favourite statistics, outright favourites have performed the best, with a win percentage of 35% and a place percentage of 65%. However, backing all favourites at Betfair SP would have resulted in an overall loss of -35.42, so it may be worth considering more selective approaches, such as only backing outright favourites or focusing on certain types of races.

Among jockeys, it may be worth paying attention to Brian D L Sayette, who has a win percentage of 30% and a place percentage of 49% from 43 rides, with a profit of 49.13 at Betfair SP. Other jockeys with potentially profitable records include Mr Billy Loughnane, Connor Murtagh, and Pat Cosgrave.

When it comes to trainers, Hugo Palmer, Andrew Balding, and Ed Walker are among those with the highest win percentages, although the latter two also have relatively high place percentages, suggesting that they may be worth backing each-way. Meanwhile, trainers such as James E Long and William S Kittow have lower win percentages but higher profits, indicating that their horses may offer value at longer odds.

Finally, among stallions, Siyouni (FR) and Pivotal have both produced horses with win percentages of 16% or higher and profitable records at Betfair SP, while Dark Angel (IRE) has a lower win percentage but has still generated a significant number of winners and may offer value at longer odds.

Potential strategies for taking advantage of these insights could include focusing on races where the favourite is an outright favourite, backing horses ridden by Brian D L Sayette or trained by Hugo Palmer or Andrew Balding, and looking for horses sired by Siyouni (FR), Pivotal, or Dark Angel (IRE) that are being offered at attractive odds. It may also be worth considering each-way bets on horses trained by Ed Walker or William S Kittow or backed by jockeys with high place percentages.