How many games

I am not able to answer nor authenticate averages nor maximums. I can only attest to what I have heard, seen & done in the past (and it probably won't change much more in the future). (And of course the qty of games is entirely dependent on the Lat/Longs from either you reside and/or where the player attends school.)

That said:

If player is not in HS (14U)
a) 40 games March to late June
b) 20 games July 1 to August
c) 20 games Aug to school start
d) 20 games Sept to Nov
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That's about 100.

If player is in HS (15-18)
a) 20 games March to late May
b) 40 games Memorial Day to mid July
c) 20 games Mid July to begin Aug
d) 40 games mid Aug to mid Nov
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That's 120.

Player is in College 18-22
a) 56 games mid Feb to late May
b) 60 games Memorial Day to mid Aug
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That's 116

Independant (or Minor League)
a) 20 games Mid Feb to April 1
b) 120 games April 1 to Sept 1
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That's 140

Major League
a) 30 games Mid Feb to April 1
b) 162 games April 1 to mid Oct
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That 192

Throw in 50 more for Arizona League, Mex & DR Winter Leagues for some of the minor leaguers and a few of the major leaguers

To determine max, take, for an example a couple of HOF pitchers. On modern day, threw over 3900 innings
in league games in a 19 yr span. That's an average of about 200 innings per year. One HOF (& WW2 vet) average over 210 innings per year in his 18 yr span. Heck Gimpy Pappas averaged about 190 innings per year for 17 yrs.