How to bet on March Madness
March Madness is the NCAA basketball tournament, and for a book it is the busiest stretch of the year outside football. The bets are the same ones you can make on any college game. What changes is who is betting, and how much the seeds get in the way of the price.
A bracket is not a bet
A bracket and a bet are opposite jobs. In a bracket pool you are up against the other entries, so the value is in being right where they are wrong, and picking a big favorite that everybody else also picked earns you nothing. Against a book you are up against the price. A top seed beating a 16 seed is not a bet at all until you know what it costs.
The usual bracket mistakes come to the betting window in another form. The player who takes every top seed in his pool takes them at the counter too, at the shortest prices of the year. The one who picks a pile of upsets because there are always upsets does the same with his money (there are always upsets, rarely the ones on your ticket).
The seed is not the line
The seeds come from a selection committee. The line comes from a book, and most books build it from the same power ratings they used all season, not from the number printed next to the team's name. A team that won a small conference can be better than the bigger school seeded above it, and the line will often say so before the bracket does. Everybody knows the 12 against 5 game is a famous upset spot, which is exactly why the 12 is rarely as long a price as the seeds would suggest.
What I'd read instead is the schedule behind the record. Say one team went 27 and 5 against weak opponents and another went 19 and 12 against good ones. Neither is what its record says, and the book knows it. Where the public doesn't, the price can lean toward the record, and that is the one place a seed helps you: it tells you what casual money will think.
Neutral courts and tempo
Every tournament game is played on a neutral court, so the home-court points that sit inside a regular-season line are gone. A team playing near home brings a bigger crowd, but tickets are often sold before the bracket is known, and a friendly crowd is not a home game. I wouldn't pay extra for it.
Tempo matters more than most bettors give it credit for. A team that plays slowly cuts the number of possessions, and fewer possessions give the better team fewer chances to pull away, which helps an underdog on the spread and pulls the total down. Before I bet a big spread in March, I'd want to know which team decides the pace.
Points or the moneyline on the dog
Say a favorite is -7.5 and -320 on the moneyline, and the underdog is +7.5 and +260. At +260 the underdog has to win outright 27.8 percent of the time for you to break even. At +7.5 and -110 it only has to stay within 7 points, or win, 52.4 percent of the time. If you think the underdog wins the game, the moneyline pays you for it; if you think it keeps the game close, take the points.
Notice what the two moneyline prices add up to: 76.2 percent for the favorite and 27.8 for the underdog, 104 in all. That extra 4 is the book's cut, the same size as on a spread at -110. You pay it either way.
Futures and the long board
Title odds go up before the season starts and stay up through the final. If you turn every price on a futures board into a percentage and add them up, the total usually comes to far more than 100, and the gap is the book's margin, much bigger than on a single game. I'd rather bet the tournament game by game than tie money up in one ticket for weeks. If you do want a future, shop it: futures prices often differ more between books than game lines do. The futures page has the arithmetic, and implied probability shows how to turn a price into a percentage.
The opening weekend
The first two rounds put 48 games on the board in four days. The most casual money of the year arrives then, and it comes in on names: the schools people know and the favorites already in their brackets. By tip-off the popular side often costs a little more than it should. The later rounds have fewer games and more eyes on each one, and by the Final Four the line has been bet by everybody, so what's left to find is mostly the difference in price between one book and another.
Choosing a book for all this is its own subject, covered on best college basketball betting sites.
What the month is worth
Decide before the tournament starts what the whole of it is worth to you, and stake from that. Say you have a $1,000 bankroll and bet $22 to win $20 on every one of those 48 opening games. That is $1,056 at risk in four days, more than the bankroll, and if you win exactly half you are down $48 for your trouble. I'd keep each bet to 1 or 2 percent of the bankroll and bet only the handful of games where you have a real opinion about the number.
The rest are for watching. That part is free.