M Ratio And Short Stack Play

M Measures How Many Orbits A Stack Can Survive Without Playing A Hand: A Stack Of 12,000 With Blinds Of 400 And 800 And An 800 Big Blind Ante Has An M Of 6, Which Is 15 Big Blinds And Short Enough To Play Push Or Fold.

Tournaments Lesson From Smarter.Poker, Updated 2026-09-22

Measuring A Stack

M, Popularised By Dan Harrington, Is Your Stack Divided By The Cost Of One Full Orbit: The Small Blind, The Big Blind And All The Antes. In The Example The Orbit Costs 400 Plus 800 Plus 800, So M Is 12000 Divided By 2000, Which Is 6. Counting In Big Blinds Gives 15. Most Players Today Talk In Big Blinds, And M Is Most Useful When Antes Make The Orbit Much More Expensive Than The Blinds Alone.

A Common Framework, From Harrington, Groups Stacks Into Zones. An M Of 20 Or More Leaves Room For All Of Poker. Between 10 And 20 You Should Avoid Speculative Hands. Between 6 And 10 You Should Look For Spots To Move All In First. Below 6 You Are Close To Push Or Fold, And Below 1 You Are All In With Almost Anything The First Time The Action Folds To You.

Harrington's Stack Zones, A Common Framework
M	Zone	What It Allows
20 Or More	Green	Full Range Of Plays, Including Speculative Hands
10 To 20	Yellow	Fewer Speculative Hands, More Raising First In
6 To 10	Orange	Moving All In First Becomes The Main Weapon
1 To 6	Red	Push Or Fold
Below 1	Dead	All In At The First Chance

Why Short Stacks Push Instead Of Raise

With A Short Stack, A Standard Raise Commits So Much Of Your Stack That You Cannot Fold To A Re-Raise, And A Re-Raise Tells Your Opponent Exactly When To Put You All In. Moving All In Yourself Removes That Problem. It Wins The Blinds And Antes Whenever Everyone Folds, And When You Are Called You Still Have Your Equity In The Hand.

That Fold Equity Is Why The First Player In Has A Large Edge Over The Player Who Calls. A Hand Strong Enough To Shove May Be Far Too Weak To Call A Shove With, Because The Caller Has No Fold Equity At All And Must Simply Be Ahead Often Enough.

Practical Tips

Act Before The Blinds Make The Decision For You. A Stack At 10 Big Blinds That Waits For A Premium Hand Can Easily Be At 6 By The Time It Arrives, And A 6 Big Blind Shove Folds Out Far Fewer Hands Than A 10 Big Blind One.

Wider Is Right From Late Position, Where Fewer Players Are Left To Wake Up With A Hand. Near The Money Bubble, ICM Makes Every Call More Expensive For The Players You Shove Into, Which Works In Your Favour, And Makes Every Elimination More Expensive For You, So Weigh Both Before You Move In.

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