In game plan is it possible to chose "Number Of Recent Games"
which is very good,
BUT I miss a related thing.

I don't know about other coaches, but I often play different and partly with other players during PREseason, so it would be nice to get possibility to EXCLUDE these matches from the statistics of results of different plays.
And it can be useful for other special situations too as for instance to exclude a period when results got much different during star players were injuried.

Suggestion:
Add a similar chose meny as the "Number Of Recent Games" (with 0 as default) where match START counting can be chosen. So it become possible to chose for instance match 5-10 back but exclude 1-4.

It's been my observation that "number of recent games" doesn't include pre-season at all.

Oh they don't?
Then we can't get same types of hints which plays to chose, if make some types of changes during preseason, as for instance when taking over a new team that time of season.

preseason is BAD way of measuring what plays work anyway. I NEVER play my starters. I usually set my plays using a lot of games (maybe last 16 or more), and then see how the numbers change when I select fewer games to get any idea of the trend of more recent play. Have to be careful though.. one good run/pass for 60+ yards can skew yds/attempt for many games. Unless I have a key pre-season addition/loss to my roster that will affect certain plays, i usually wait until after week 4 to begin tweaking playbook.

In regards to pre-season, I'll never watch more than a half's worth of action. (first half)

I'll only observe off the visual from the first half and disregard the second half.

However, you can't filter that at the end of pre-season when you're judging what worked and didn't work so I'll take the totality of all 4 games and that'll allow me to see what to remove...primariy on one side of the ball. Your guess on which side. :P

Preseason can be useful if you are writing rules and you want to observe how they work (and that they don't conflict).

Once your rules are set up, there isn't a lot to be learned from preseason except maybe a battle among players for the final few spots on the roster.

I agree with you basicly,
but when taking over a new team, some info about changes is a bit better than no info :)