http://www.geocities.com/cpa68/ratings.html
Link breaks down all player abilities. below tells in detail what each attribute stands for/how it works.
Max - (Maximum/Top Speed) This is simply the player's maximum running speed. The higher the rating the faster. Bo Jackson has the highest max rating out of the offense players with 11. The highest for a defensive player is 18, with six players tied at that mark.
Initial - (Starting Speed) This is how fast a player will run before they reach top speeed. The higher the better, as players with high ratings are more able to cut and juke without slowing down. Most players have 0 or 1 in this catergory. The better running backs and kick returners have a 4, while the best defenders (Taylor and Lott) have a 3.
Accel - (Acceleration) This determines how quickly a player will reach his maximum speed. For this catergory the lower the rating the better. Almost every offensive player in the game has a 3 rating, while defenders are usually 8 or 9, with the star defenders getting a 7.
Power - This determines the player's ability to make popcorn and break or make tackles. The higher the better. Kevin Mack is the most powerful offensive player with an 88 rating. Lawrence Taylor has the highest rating for a defensive player with 86.
Arm - You won't find the arm catergory on the Tecmo Bowl rom manager. I created this catergory by simply taking the average special rating for each team's receivers. For example Miami's wide receivers both have a 14 special rating, their tight end has a 14 rating and their running back has a 14 rating. Add it together to get 56, divide by the 4 receivers, and it averages to, surprisingly, a 14 rating. This represents the average throwing speed for the quarterback. The higher the better. Marino is the highest with 14, Trudeau the lowest with 8.75.
Special - For offensive players this rating determines how quickly the quarterback will throw the ball to that plyer. All wide receivers on the same team usually have the same special rating, so the rating is determined by the quarterback.
What this catergory does for quarterbacks is a mystery. Only John Elway has a different rating then the rest.
For kickers and punters this determines how far they can kick/punt the ball. The higher the better. Dean Biasucci and Kevin Butler have the best rating for kickers with 10, while Sean Landeta has the best rating for punters with a 14.