MMA Weights and Winning

Most competitions have 8 weight classes. (random fun fact lbs is for star sign Libra. The symbol for Libra is the scales)

Flyweight - 57kg/125lbs
Bantamweight - 61kg/135lbs
Featherweight - 66kg/145lbs
Lightweight - 70kg/155lbs
Welterweight - 77kg/170lbs
Middleweight - 84kg/185lbs
Light Heavyweight - 93kg/205lbs
Heavyweight - 120kg/265lbs 

The lighter end of the spectrum is known for being quick and agile, while the heavier weights are known for their hard hands (knockout power) and good grappling (mostly wrestling, judo and sambo)


For ways to win you can do the following to your opponent
Knockout - K.O - pretty self explanatory (you are unconscious for any period of time)
Technical Knockout - TKO - the referee thinks the opponent is unable to continue the match 
Submission - again, pretty self explanatory (arm bar, kimora, rear naked choke, triangle, etc)
Decision - The fighters fight all rounds (3-5) and a panel of 3 judges score each round (usually out of 10) and the person with the most points wins. These points are based on the number of take downs, submission attempts, how many kicks and punches landed)
               - Unanimous Decision is when all 3 judges agree on the winner
               - Split Decision is when 2 judges agree on 1 fighter winning and the 3rd judge
                 scores in the other fighters favour
               - Majority Decision is when 2 judges agree on a winner and the 3rd judge says the 
                 fight was a draw
               - Minority Draw is when 1 judge scores in favour of one fighter and the 2 other 
                 judges agree the fight was a draw

If you want a closer look at rules and regulations here are the rules that are UFC sanctioned. 

Current UFC Champions (as of may 2014)
Fly - Demetrious Johnson
Bantam Mens - Renan Barao
Bantam Women - Ronda Rousey
Feather - Jose Aldo
Light - Anthony Pettis
Welter - Johny Hendricks
Middle - Chris Weidman
Light Heavy - Jon Jones
Heavy - Cain Velasquez

Current Bellator Champions (as of may 2014)
Bantam - Eduardo Dantas
Feather - Pat Curran
Light - Eddie Alvares
Welter - Doug Lima
Middle - Alexander Shlemenko
Light Heavy - Emanuel Newton
Heavy - Vitaly Minakov

PRIDE FC Champions (PRIDE finished in 2007)
Light - Tankanori Gomi
Welter - Dan Henderson
Middle - Dan Henderson
Heavy - Fedor Emelianenko