Best prop-builder software

What it is

Every per-head package comes with props already on the board, written by the shop's line movers. A prop builder is a screen in the agent's back office where you add your own. You type the question, set the options and the price, choose which players can see it and how much each can bet, and the software takes the tickets like any other bet.

Most builders handle the usual shapes: a yes or no, an over or under on a number, a head-to-head between two players, or a list of outcomes with a price on each. The props guide covers the bets from the player's side.

Why players like them

A player who has a bookie wants something the big books don't give him, and a prop on the game he and his friends will be watching is one of those things. It makes your package feel like yours. I always found that the players who bet the odd props were the recreational ones, and recreational action is what a bookie lives on.

The number is yours, and so is the risk

When the shop posts a line, it has the market behind it. When you post a prop, the only thing behind the number is you. If it is wrong, nobody moves it until you do, and the first player to notice will bet it every time.

The danger isn't the bettor who guesses. It's the bettor who knows: the friend of the player, the one who saw the injury report first. A custom prop is a small market with no one else watching it, which is exactly where that bettor looks.

So I'd protect myself three ways. Keep the limit low, far below what the same player can bet on a side, so that a bad number costs you a small amount a few times rather than a large amount once. Charge more juice than on a side. At -110 on both sides the theoretical hold is 4.55 percent; at -130 on both sides it is 11.5 percent, and the player has to win 56.52 percent of the time to break even, which gives your number room to be a little off. And take it down the moment the action all comes one way. The wider sums are on the risk management page.

Grading

A custom prop is graded by whoever wrote it, and that is usually you. Write the rule before the first bet: what counts, which source decides, what happens if the game is postponed or the player doesn't play. A prop with a loose rule turns into an argument on settling day, and I've never seen an argument with a player that was worth the money in it.

What to check

When you look at a package, open the builder and write a real prop before you sign. These are the things I'd test:

• Limits per prop and per player, separate from the limits on sides.
• Your own price on each side, not a fixed juice.
• One click to suspend or pull a prop.
• Who can see it: all players, some, or one.
• An exposure line for each prop in the open-bets report.
• Grading that is quick and leaves a record of what you decided.

A builder without the first three is a way to hand out money. And put a figure on what you are prepared to lose on the props in a week, the same way you would on anything else. They are a sideline. Book them like one.