That would depend on whether the pitcher is a starter or reliever.
A starting pitcher generally pitches 1 game every 5 days because they pitch a lot of innings each game. Over an MLB season this would mean the #1 starter on a team, over the course of a season where they did not miss a start, would pitch 33-35 games per season. The #1 might get an extra start or two in a season in situations where the team had a day off and the manager decided to go with the #1 starter in a game as opposed to the #5 starter since the #1 had his required number of days of rest. Two of the best starting pitchers in MLB in 2010, Roy Halladay and C.C. Sabathia, pitched in 33 and 34 games, respectively.
A relief pitcher, especially a closer or pitcher that is brought to pitch to only one batter, could pitch in many more games than a starting pitcher because they don't pitch as many innings as a starting pitcher. Two of the best closers in MLB in 2010, Brian Wilson and Rafael Soriano, pitched in 70 and 64 games, respectively. Generally, they pitched only one inning per game.
Two of the best situation pitchers in MLB in 2010, Pedro Feliciano and Randy Choate, pitched in 92 and 85 games, respectively. Feliciano pitched in 62 2/3 innings and Choate pitched in 44 2/3 innings. In many games these guys, both left handers, were brought in to face only one or two hitters who were left handed.
An NFL player will play 16 regular season games and 4 or 5 preseason games (most teams play 4 preseason games but the teams that play in the Hall of Fame game play 5). Should his team make the playoffs, he can also play 3 or 4 more games depending on where he team winds up in the Conference rankings and if his team makes it to the Super Bowl. So an NFL player, should he stay healthy and not be injured, would play between 23 and 25 games in a season.
The NCAA has no rules governing how many pitches a pitcher can throw in a game and how often he can pitch.
Pitch count has nothing to do with eligibility to be the winning pitcher. In a scheduled 9-inning game, the starting pitcher must pitch 5 complete innings to be eligible to be the winning pitcher. Relief pitchers must be the pitcher of record when the winning team takes the lead, and never relinquishes the lead, to be the winning pitcher.
Depends on how many pitches are thrown
3 pitches...
Are there any limits on how many innings a pitcher can pitch, in one game? Not in any official rules. In a MLB game on 1920 May 5, both pitchers threw for 26 innings. The game was called due to darkness with the score still 1 to 1.
Pitchers in MLB and the minor leagues get eight warmup pitches when entering a game unless they are entering the game due to an injury to the previous pitcher. If the previous pitcher was injured the relieving pitcher may take as many warmup pitches as the umpire deems necessary. Rule 8.03
120
They have to pitch the complete game...
65
It depends on how many pitches he throws. When he throws more than 80 or more pitches that's probably when he wll be taken out.
A pitcher should work up to the amount of pitches that they will usually throw if they are going to pitch the entire game. That is usually somewhere around 125 pitches. Better to be over prepared than under prepared.
every single pitch that is not called as a strike.