types:
agonist
someone involved in a contest or battle (as in an agon)
entrant
one who enters a competition
long shot
a contestant that is unlikely to win
outsider
a contestant (human or animal) not considered to have a good chance to win
pothunter
someone who participates in contests in order to collect trophies
qualifier
a contestant who meets certain requirements and so qualifies to take part in the next stage of competition
starter
a contestant in a team sport who is in the game at the beginning
withdrawer
a contestant who withdraws from competition
contestee
a winner (of a race or an election etc.) whose victory is contested
acrobat
an athlete who performs acts requiring skill and agility and coordination
amateur
an athlete who does not play for pay
ball hawk
a team athlete who is skilled at stealing or catching the ball
bowler
a player who rolls balls down an alley at pins
card player
someone who plays (or knows how to play) card games
climber
someone who climbs as a sport; especially someone who climbs mountains
comer
someone with a promising future
finalist
a contestant who reaches the final stages of a competition
grandmaster
a player of exceptional or world class skill in chess or bridge
gymnast
an athlete who is skilled in gymnastics
hooker
(rugby) the player in the middle of the front row of the scrum who tries to capture the ball with the foot
hurdler
an athlete who runs the hurdles
jumper
an athlete who competes at jumping
letterman
an athlete who has earned a letter in a school sport
old maid
the loser in a game of old maid
Olympian
an athlete who participates in the Olympic games
playmaker
a player in a team sport who leads attacks or maneuvers in such a way that a teammate can score
runner
a trained athlete who competes in foot races
scorer
a player who makes a score in a game or contest
scratch
a competitor who has withdrawn from competition
semifinalist
one of four competitors remaining in a tournament by elimination
server
(court games) the player who serves to start a point
shooter
(sports) a player who drives or kicks a ball at the goal (or a basketball player who shoots at the basket)
street fighter
a contestant who is very aggressive and willing to use underhand methods
swimmer
a trained athlete who participates in swimming meets
swinger
someone who swings sports implements
tier
any one of two or more competitors who tie one another
tilter
someone who engages in a tilt or joust
upsetter
an unexpected winner; someone who defeats the favorite competitor
winger
(sports) player in wing position