M‑Ratio (M)
M-ratio, or M, measures how many rounds of forced bets your stack can pay for in a tournament. It is your stack divided by the cost of one orbit: the small blind, the big blind and the antes.
The simple explanation
If you have 10,000 chips and the blinds and antes cost 500 chips per round, your M is 20. This means you can last about 20 orbits without playing a hand. The lower the M, the less time you have and the more urgent it is to act.
A closer look
The measure was introduced by Dan Harrington. He describes zones: above 20 is the green zone, in which you can play normally; 10 to 20 is yellow; 6 to 10 is orange; 1 to 5 is red, where you can only push all in or fold; and below 1 you are in the dead zone. M tells you how much flexibility you have. Unlike the number of big blinds, M includes antes, so it is more exact in late stages with antes. In a full table, the cost is for nine players, and it falls as players leave, so many people use the effective M for the table.
A practical example
A player has 10,000 chips, the blinds are 100/200 and the ante is 25 with nine players. One orbit costs 300 + 225 = 525, so the M is about 19.
Full explanation
M-ratio, or M, measures how many rounds of forced bets your stack can pay for in a tournament. It is your stack divided by the cost of one orbit: the small blind, the big blind and the antes.
M-ratio is a stack divided by the cost of one round of blinds and antes.
It tells you how many rounds you can survive without playing a hand.
Low M means that you have to take risks soon.
The idea comes from Dan Harrington.
Alternative spelling: M-Ratio, M Ratio, M