These are taken from MLFS and are PES3 stats with my own explanation, so they may have different names or 1 or 2 missing that are in PES4, and are what I think they mean:
Offence: How well suited a player is to attacking posotions, such as striker or offensive midfield
Defence: Likewise, how suited a player is to dfesnesive positions, such as goalkeeper and the entire back four
Body Balance: The chance a player will fall over when going shoulder to shoulder - the higher the rating, the better chance he has of staying on his feet
Stamina: How long a player can sprint or run for before he gets tired and slows down
Top Speed: The speed at which he can run when in full flight (R1)
Acceleration: How long it takes a player to reach top speed - the higher the rating the sooner he is in full sprint
Response: How quickly a player reacts to a loose ball, so if a deflected shot came to a striker with a high response, the better chance he has of reacting and putting it away
Agility: How far a player can stretch when reaching for a ball
Dribble Accuracy: How well a player can dribble the ball. The higher the rating, the closer the ball stays to his feet when moving at high speeds
Dribble Speed; How fast a player can run when he has the ball at his feet - this is relative to his speed rating (running without the ball)
Short Pass Accuracy: How well the player can pick out a team mate with a pass along the floor (X)
Short Pass Speed: The pace the player puts on the ball when passing to a team-mate - the higher the rating and the faster the pass, the les chance of an interception
Long Pass Accuracy: How well a player can direct an aerial pass (O)
Long Pass Speed: The pace which the player puts on a aerial pass
Shot Accuracy: The accuracy a player can shot with - the higher this is the more often the player will hit the target from long range, and when one-on-one with keeper he is more likely to put it past him
Shoot Power: The power the player can put into a shot. The higher a players rating the harder he can hit the ball. A shot with lots of power is more likely to surprise the keeper
Shoot Technique: How well a player can shot from different positions. A player with high shot technique can score from almost anywhere in the penalty area, and most positions outside of it
Free kick accuracy: How well the player can aim a free-kick. A high rating means he is more likely to put it in a top corner
Curving: How much curl a player can put on the ball. This is useful for set-pieces, but I'm not sure how effective this is from open play
Header: How well the player can aim a header and how much power he can put into it. This applies to both defensive and attacking headers. A high rating means the player is more likely to connect
Jump: How high a player can jump when challenging for a ball in the air
Technique: A players first touch. A player with high technique will be able to control the ball without letting it bounce first, and will be better at volleys and first time passes
Agression: How attack minded a player is. A player with high rating will be more likely to run at goal then pass it around the midfield
Mentality: How much a player will let a bad performance affect him. If he misses a few easy chances, he will still feel confident enough to shoot
Play Stability: How consistent a player is. If he has high in this, he will be more likely to play well throughout the game and overall several matches
Goalkeeping Skill: How good a player is at blocking shots (this applies to keepers using their hands)
Team Work Ability: How well a player plays as a team - whether he is greedy and will run a lot with the ball or whether he will play a lot of passes
Condition Stability: How long a player can maintain his fitness for - a low rating means he may burn out after not long
Well that's what I think anyway - feel free to copy and paste this and alter it with your own corrections
