• Some teams have difficulty finding the requisite number of players of the opposite sex and end up losing the game by default because of it.
• When Co-ed teams are lacking in players of a specific sex, the few players available are obliged to play much longer than usual. They are often very tired by the end of the game and team performance generally suffers for it.

- Lack of Quality:

• Many men, who are usually faster and stronger than women, get frustrated when they face women and find they have to slow down. They may end up not enjoying themselves and may also feel they can’t express themselves fully.
• Women can experience frustration as well. Often, they are not taken seriously during the game by men who are afraid of hurting or overpowering them.
• The fact that players in Co-ed leagues try to be gentle with one another can affect the game in a negative way. More competitive players might not enjoy the game as much.

- Rare, but Severe Injuries:

• Sport injuries that occur when weaker players try to perform at the same level as stronger players of the opposite sex can be dangerous.
• Some players who don't understand the game and get invited just to fill the quota sometimes don't understand the concept of tackle, shield, advantage, "First to the ball" and can create injuries by doing things that the opponents are not expecting. It sometimes results in very bad injuries.
• Clumsy players who join the game to fill the quota or just to play with their date or partner usually end up hurting themselves or their opponent by not knowing when to slow down or get away from players who are very fast or skillful.

- Jealousy:

• The potential attraction between players of opposing sexes can sometimes create conflicts and jealousy from other players and this can affect the game negatively.
• Some players go to specific teams just to court other players from the opposite sex and the game is not their priority. This can affect the game negatively.
• Some players can be rejected by a love interest in the same team and they don't always cope well with the rejection. In those cases, the atmosphere of the team is sometimes ruined and the team ends up losing at least one of the players concerned. When teams lose female members, it is hard to replace them and they end up forfeiting some games by not having enough female members.

- Statistics of Co-Ed Sport Teams vs Men Teams and Women Teams:

To conclude:

• Co-ed sports or mixed gender teams are when both females and males play on the same team. Co-ed games can either be joining forces to play against another co-ed team or in some cases, males and females play against each other. In recent years, it has become more popular for organizations to require that children playing sports must be co-ed. There are many different opinions when it comes to co-ed games. Some people feel that it is important for boys and girls to play sports together so that they can learn how to work together and understand each other. Co-ed sports can teach players about communication, teamwork, and cooperation skills. Playing with people of the opposite sex can also help children become more comfortable interacting with members of the opposite sex. It can also help them to understand and accept people who are transgender or have a different gender identity than they do. On the other hand, some people feel that co-ed sports can be unfair to either gender. They may feel that one gender is not given the same opportunity to succeed as the other or that the games are not as safe as they could be if they were single-gender.
  Co-ed games or sports are those where both genders participate in the same game or sport. Co-ed games are not new, they have been around for centuries. Co-ed sports teams started gaining popularity in the early nineteenth century and by the mid-twentieth century, co-ed sports were being played at the high school and collegiate level. Co-ed sports teams provide an opportunity for members of both sexes to compete against each other on an equal playing field. There are pros and cons to playing on a co-ed team and each player needs to decide what is best for them. Some of the pros of playing on a co-ed team include:
  1) Co-ed teams provide an opportunity for players of both sexes to compete against each other on an equal playing field. This can help to level the playing field when it comes to physicality and skill.
  2) Co-ed teams can provide a healthy environment for players to socialize with members of the opposite sex. This can help players to develop healthy relationships with members of the opposite sex.
  3) Co-ed teams can help players to develop leadership skills. Players need to learn how to work together as a team in order to be successful.
  
• Co-ed games or mixed team sports have more positives than negatives. However, I recommend it for mature, older players as they are more likely to have the patience and self-control to enjoy this type of game. Kids under 6 can also play co-ed for a practical reason. At that age, there are not just enough girls to form a complete team in a girl only league. At that age also, boys and girl can safely play together without any need of self control.
• On a recreational and amateur level, many sports feature co-ed teams and leagues and it is growing very fast. The most notables amateur sports with co-ed leagues and teams are soccer, basketball, volleyball, ultimate frisbee, softball, flag football. Official competitions featuring co-ed or mixed teams so far are limited to ultimate Frisbee, double tennis, equestrian

Various Question and Answers about Co-Ed Sport games, teams and leagues around the world

Are the Co-Ed Sports in NCAA?

At the NCAA college level, there are three sports that are specifically designed to have both male and female members of the same team.

1. Fencing
2. Rifle
3. Skiing

In these sports, men and women compete separately, but only one championship is awarded.

In addition, many women have competed on men’s teams, such as baseball and football

Should men take it easy on women in co-ed sports?

For the co-ed flag football, the league had rules to keep it fair. One of them was that if “blocked” we had to run around the opponent, but the opponent had to establish position (e.g. like in basketball). On one punt, I was running down field to get the opposing player with the ball when one of their female players (the team captain) stepped in front of me at the last moment. I literally ran her over on the way to the player with the ball. She ran over to the referee, and I can still picture the referee looking at her and then at me and then turning to her and saying: “Why would you Ever step in front of Stagliano?”

Does FIFA allow women on men's football (soccer) teams if they are good enough?

• According to FIFA, it is a local issue: they have no ban on women playing in the men’s game.
  Read Sam Sinai's answer to When will FIFA allow men and women playing football together? on Quora
• Read Sam Sinai's answer to When will FIFA allow men and women playing football together? on Quora

What sport, played or competed by both genders respectively, in which women are more dominant than men?

• Gymnastics
• Figure Skating
• Netball
• Synchronized Swimming
• Roller Derby
• Softball
• Roller Derby
• Field Hockey

Why do we still have separate men and women categories in sports, when we both are equal?

In what sport can male and female athletes compete with each other professionally?

What sports would women match up equally to be able to play? If we are talking about competing at the same level?.
Possibly basketball? Not sure the strength differential would allow women to compete successfully overall.

Ice hockey? Again, the contact aspect would make it difficult.
Baseball? Football? Maybe, maybe at certain positions but again, very difficult.
Now, I have played in some of these sports at a high amateur level with women who were excellent players in each. I have also played against and with pro players in all 4 major sports and the difference in skill level of those players is astounding.
If there were interest (and an audience for) co-ed sports at a serious level, I’m sure it would appeal to some curiosity of fans, to see male and female athletes trying their best on a co-ed team. And maybe certain sports, like bowling would eliminate the physical differences. But in head-to-head matchups of best vs best, I don’t see a matchup (say for historical purposes, a Lisa Leslie matching up against Jabbar or Olajuwon) coming out very well for female players. Or a top female softball player doing much against Gerritt Cole’s fastball or slider.
It might work if the men played by women’s rules, could be fun to watch MLB players playing fast-pitch softball.

• Motor sports: There is no restriction on female drivers in 4 wheel motor sports - I am not sure about motorbikes - but certainly not in cars. You mention Danica Patrick but I think Maryeve Dufault has competed in Nascar also. Milka Duno has competed in Indycar and there have been a number of female F1 racers the best of whom was probably Lella Lombardi who competed in 17 F1 Grand Prix, and is to date the only female driver to have scored world championship points. She was a good sports car driver too. The most recent was María de Villota who was a test driver for the Marussia team in 2012 until she crashed in testing.
• Equestrian sports: Its strange to think that this most old fashioned of sports - is perhaps the one with the most equality. Men and women compete equally in showjumping, dressage, and cross country . In Dressage, women have won the Olympic Gold Medal at the last 7 Olympics, and in the last 4 Olympics have won all 3 medals. In Eventing women have won individual silver and bronze at the last 3 Olympics and team gold at the last 2, and in Showjumping women won gold, silver and bronze team medals at Beijing. Anne, Princess Royal even competed in the Olympics for Great Britain
• Horse Racing: There have been quite a few female jockeys in the US, the first licensed jockey being Penny Ann Early and the most successful probably being Donna Barton Brothers
• Sailing - Ocean Racing: Olympic sailing segregates male and female participants, but in long distance racing there are no restrictions. For example, more than a thousand women have competed in the Sydney to Hobart Yacht Race
• Racquet Sports: Mixed doubles are competed in most racquet sports, such as tennis, badminton and table tennis. But there is no "open" competition
• Chess: Although male dominated, men and women can play each other in open competition. The most successful female chess player is Judit Polgár
• Curling: A mixed doubles competition is available for curling
• Ice Skating: Skating features mixed Ice Dance, and Ice Dancing competitions, but no open competition for men and women to compete openly against each other
• Climbing: Climbing is mainly based on open competition