Here's a factor that I'd like to see stats on.
Number or percentage of wins and or "good" races in past 12 ,excluding "irrelevant" races and races prior to a 90 day layoff and including/excluding QES or Speed rating rank.A high percentage ( 80% or better) has been 1 of my tools but knowing the actual long term win % would i be helpful .

Yes! My first winner came about by the most rudimentary "handicapping". I had only a track program and hadn't heard of Daily Racing Form but it seemed to me that betting on a horse to do something that it had done before ( win a race at the distance) might be prudent. The race was 1 1/16 for mid-level claimers on dirt at our local bull ring . "Picture Frame" had won at 1m twice .
He closed at 9/1, broke on top and lead all the way! I still insist on some previous success

How much of an advantage ( in percentage) is needed to produce a profitable play.

Highest QES points percentage (of field total) might be interesting.