Water polo is a phenomenal sport. I played it for 10 years, and have been an active age group and high school referee for 15 of the last 20 years. I have seen a lot of water polo. After many discussions with parents, coaches and other referees about what makes a good water polo, I thought it worthwhile to put my thoughts out here.
A good water polo player is at strong in all of the following traits. A great water polo player is exceptional in several, with none of them a weakness.
Awareness and Anticipation
Water polo is fast moving and complicated. A good player knows the rules and understands the game. When playing, he knows the game situation (period, time, shot clock, score, etc.), what is happening in the pool, where his teammates are and what they are trying to do, and where his opponents are and what they are trying to do as well. He is anticipating what will happen as well as reacting to what is happening.  Situational awareness is the key to good team defense, because a player has to know what is happening in order to help a teammate.
Aggressiveness
By aggressive, I do not mean combative or itching for conflict. I use aggressive to mean the resilient, alert, active, focused and persistent. A good water polo player never gives up on a game or a play. He never gives the opponent an easy pass or shot, and doesn’t loaf or play at less than 100%.
Poise and Emotional Control
Success at water polo requires emotional resilience. Referee decisions do not make sense (or are plain wrong), and the players must continue past it quickly. It can be frustrating because the player can do everything right and still be unsuccessful. Â Water polo is a physical sport, and good players are able to accept contact without losing focus. Â A good player must not allow “trash talking” or physical contact to impact concentration or focus.
Agility and Balance
Agility and balance are just as important in water polo as in land sports.  A good water polo player moves easily in the water, and is comfortable moving and changing direction using only the legs.  The ability to absorb contact and remain agile is critical, as is the ability to quickly rise out of the water and quickly move laterally.  Good natural athletes can  generally pick this up, but the movements are not natural and must be drilled.  One evidence of excellent coaching at a program is that the athletes are uniformly solid in this area of the game.
Ball Skills
The goal of the game is to win, and in order to win the ball be put into the goal. Â Accurate passing and shooting is absolutely necessary for success. Â A pass can’t just get in the general area of the target, it must be precisely placed to allow the recipient to act quickly. Â It must have enough velocity to get to the destination and be caught, but not too much velocity. Â Good players have the skill, poise, and body control to make precise passes even when being pressured by a defender. Â And good players have excellent hands, meaning that they can control the ball even when it isn’t precisely placed.
The ability to pass under pressure is the single biggest difference between a good team and a mediocre team.
Physical Condition
Water polo is a far more physically demanding sport than basketball, soccer or lacrosse. Â It is played in the water, and all players except the goalkeeper play offense and defense. Stamina is a requirement for water polo excellence, because there is no resting against a quality opponent. Â Physical strength (particularly in the legs) is also necessary, because of the high degree of contact. Â Leg strength allows the player to hold position and not be moved by an opponent.
what do i do to have all these kind of stuff, (to be the ONE)!
Find good coaching, work consistently hard, and watch as much high quality water polo as you can.
Also, learn to be a timekeeper and scorekeeper; it will help you know the rules really well.
This is the first article I’ve seen that calls out emotional intelligence as a key to success. There are so many split second decisions about responding to teammates, opponents and referees. I completely agree with you on this one.