Three years ago, I created a March Madness knockout pool that none other than Cousin Sal (one of the great gamblers of all time, or at least one of the least successful) called “the best office pool ever.” I don’t know anyone who doesn’t absolutely love this pool. Anyway, here’s how it works.

• Let’s say $20 per entry, if gambling were legal.

• You have to send in your picks before the start of the first game on Thursday. No exceptions.

• For Thursday of Round 1, you have to pick TWO WINNERS. Not against the spread, just outright winners — again, both teams just have to win. If either loses, you’re out … but you can buy back in for another $20 (and if you buy back in, you have to pick FOUR winners on Friday, not two).

• For Friday, same thing if you advanced … you have to pick TWO more winners. Both teams have to win. If either of them loses, you’re out … but you can buy back in on Saturday for another $20 (only now, you have to pick FIVE winners that day and go 5-for-5 to stay alive).

• You can only buy back in a maximum of three times (and you can’t buy in after the conclusion of Saturday’s games).

• You cannot pick the same team twice. Even if you get knocked out and buy back in, you can’t reuse a team. One and done.

• If you nailed your Friday pick (or picks), you only have to pick one winner on Saturday.

• If you lose your Saturday pick (or any one of your Saturday picks), you can buy back in for Sunday’s games for the final time … only now, you have to pick SIX winners that day and go 6-for-6 to stay alive. And again, you can’t pick a team you already used.

• If you nailed your Saturday pick (or picks), you only have to pick one winner on Sunday to advance. Can’t be a team you already used.

• If you make it out of the weekend alive, you only have to pick one winner per day after that. (Again, you can’t buy back in after that first Sunday.) Remember, you can’t use the same team twice. I hate to keep harping on this, but you’d be amazed how many times it’s been screwed up in our pool.

• Once you run out of teams to pick, you advance to the next day but automatically lose. For instance, let’s say you already used Duke in Round 1 and Kentucky in Round 2, then they met on Sunday in the Elite 8 … only you had already picked every other team playing that Sunday. In that scenario, you automatically lose on the next day of games (in this case, Saturday of the Final 4). You are out of teams.

• Important wrinkle for that last point: Even if you’re out of teams and headed for an automatic loss, you still have to be beaten by another contestant who made a successful pick that same day. An “automatic loss” and “a pick that became a loss” means the same.

• Last man standing wins. Winner takes all. Second-place prizes are for wusses.

• If more than one person is left standing, they can either split the pot or agree to keep going until someone wins … which is obviously the manly thing to do.

• Honor system goes for the entry fees — once someone wins, everyone sends him their 20 bucks (or more than that if they bought back in). If you don’t trust someone to pay his debts, then he shouldn’t be in the pool.

• Last note: You’d be amazed how quickly this pool ends. Last March, we did it with 27 people and everyone was done by Sunday of the first weekend. You read that correctly.

Enjoy the Grantland March Madness knockout pool, and happy gambling.