Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Down But Not Out (5 points): Get a hit with 2 strikes on Pro or higher, in a non-simulated game.
Grab Some Pine (5 points): Get a strikeout to end the inning on Pro or higher, in a non-simulated game.
Run the Risk (10 points): Steal a base after the 6th inning tied or down by 1 run on Pro or higher, in a non-simulated game.
A Pitcher's Best Friend (10 points): Turn a double play on Pro or higher, in a non-simulated game.
To the Rescue (10 points): Bring in a pitcher, get a save with the tying run on base on Pro or higher, in a non-simulated game.
A Virtue (20 points): Face 10 pitches as the batter on Pro or higher, in a non-simulated game.
Don't Call it a Comeback (20 points): Win after being down by 4 after the 6th inning on Pro or higher, in a non-simulated game.
Keep on Truckin' (10 points): Truck the Catcher and score on Pro or higher, in a non-simulated game.
This is Why I'm Here (15 points): Be successful in a major league clutch moment in My Player Mode.
Trifectas Maximus (10 points): Throw a MAX pitch 3 consecutive times with Total Control on Pro or higher, in a non-simulated game.
One Man Show (80 points): Throw a Perfect Game or a No-Hitter on Pro or higher in a 9 inning game, in a non-simulated game.
Time to Run for Mayor (30 points): Hit 3 Home Runs in a single game with the same player on Pro or higher, in a non-simulated game.
I came, I saw... (20 points): Hit a Walk-off Home Run on Pro or higher, in a non-simulated game.
Stooges (10 points): Strikeout all three hitters in the inning on Pro or higher, in a non-simulated game.
High Crimes (20 points): Rob a Home Run on Pro or higher, in a non-simulated game.
Thou Shalt Not (10 points): Throw out a runner stealing a base on Pro or higher, in a non-simulated game.
State Farm - The Road to Victory (20 points): Get 3 consecutive batters on base on Pro or higher, in a non-simulated game.
Still Kicking (10 points): Strike out a batter with a pitcher who has low composure on Pro or higher, in a non-simulated game.
It's Never Too Late (10 points): Get a 2-out RBI Hit on Pro or higher, in a non-simulated game.
The Call (20 points): Get called up to the Majors in My Player Mode.
The Goal (10 points): Accomplish a Team Season Goal in My Player Mode.
The Top (30 points): Become the #1 ranked player in your My Player organization.
The Star (40 points): Make the All-Star team in My Player Mode.
The Start (10 points): Get your player's overall rating to 65 in My Player Mode.
The Truth (20 points): Get your player's overall rating to 85 in My Player Mode.
The Hall (80 points): Make the Hall of Fame in My Player Mode.
One and O (10 points): Play and win opening day in Franchise Mode.
What's Your Ring Size? (80 points): Win a World Series in Franchise Mode. (play at least 20 games)
Remember Me (20 points): Break a record in Franchise Mode. (play at least 20 games)
Booked a Ticket (20 points): Clinch a Postseason Berth in Franchise Mode. (play at least 20 games)
A Day in the Life (10 points): Play a game of MLB Today.
Mid-Summer Classic (40 points): Play the All-Star game in MLB Today.
King of the Hill (20 points): Get to the top of the Best of the Best ladder in Home Run Derby Mode.
My Fellow Man (10 points): Complete and win an online league game.
The Team to Beat (10 points): Beat the New York Yankees in a completed online match.
Count it (10 points): Complete and win a ranked match.
The Road to Greatness (20 points): Complete and win 3 ranked matches in a row.
The spice of life (20 points): Complete 10 online matches using 10 different teams.
Domination (20 points): Strikeout 200 batters with your user profile.
Production (20 points): Drive in 250 RBI with your user profile.
A Whole New You (5 points): Choose a signature batting stance or pitching delivery in My Player or Create Player.
Learning the Ropes (10 points): Achieve gold in all the drills.
Hurlers (10 points): Unlock 20 pitcher cards.
Swingers (10 points): Unlock 25 hitter cards.

Additionally, there are six secret achievements:

Round and Round We Go (30 points): Bat around (all 9 players bat in the same inning) on Pro or higher, in a non-simulated game.
EpidemiK (20 points): Complete an online game against a 2K developer or a player who already has this achievement.
Upset Alert (10 points): Use the Nationals in a completed ranked match.
Big Bang (30 points): Leadoff the game with a Home Run on Pro or higher, in a non-simulated game.
Back From the Brink (20 points): Get out of a bases loaded jam (0 outs, no runs scored) on Pro or higher, in a non-simulated game.
Hawkeye (10 points): Draw a walk on a full count on Pro or higher, in a non-simulated game.