Who doesn't love bonus bets from your favorite online sportsbooks? You may get them for signing up, or through another promotion or boost for existing users.
While most people just fire away, there are actually two optimal ways to use bonus bets (and it's not betting a huge favorite to lock in profits).
How to Use Bonus Bets
Method 1: Betting at Plus Money
The best way to use bonus bets, because you don't keep the bonus bet itself, is to make plus-money wagers. This will give you the most expected value — defined as how much you can expect to win if you made the bet an infinite amount of times.
Here are the things I'm looking for when finding these opportunities:
- You want to make these bets in the +300 to +600 range, because you don't have an infinite number of bonus bets. So even if you're making "+EV" bets at 100-1, it's unlikely you'll hit one with enough frequency to make any actual money.
- You want to bet into tight, two-way markets, meaning the gap between each side of the bet is small (like +300 on the underdog and -360 on the favorite on an NBA moneyline, as opposed to +400 on the underdog and -950 on the favorite on an obscure prop). The smaller the gap between two sides, the more confident a sportsbook is in the pricing.
- You want the side you're betting to be favorable to prices across the market; so if you have a $25 bonus bet at DraftKings, DK should have a good price on that bet compared to other sportsbooks.
So why is betting at plus-money more valuable?
If someone offered you +110 on a single coin toss, you should always take it, even though you'll lose 50% of the time, right? That's the crux of expected value.
The math for expected value (EV) is simple — multiply the probability of the bet winning by the amount you can expect to win. So it's what you'd win or lose on that bet if it were placed an infinite number of times.
Take these three examples from a $50 bonus bet:
| Odds | Win Amount | Probability | EV |
|---|---|---|---|
| -250 | $20 | 71.43% | +$14.28 |
| +250 | $125 | 28.57% | +$35.71 |
| +500 | $250 | 16.67% | +$41.67 |
Because you're not getting the stake back like you would with a normal bet, it’s mathematically impossible to get a better advantage over the sportsbook on a favorite than on an underdog with a free bet. The longer the odds, the more value you get.
But as I said above, you don't have an infinite number of bonus bets, so this theoretical value may not turn out to be real money if your 100-1 underdogs keep losing. That's why +300 to +600 is a nice sweet spot between actually winning money and getting maximum value.
Method 2: "Converting" Bonus Bets to Cash
With bonus bet conversion, you can lock in a profit by hedging against another sportsbook. Just find two lines that are close together, and bet them at different books. Do not bet opposite sides at the same book, or you'll likely be limited or banned for this practice.
Plenty of tools find these conversion opportunities, like Crazy Ninja Odds. You can sort by the most profitable conversion opportunities at the sportsbook where you have your bonus bets.
In the example above with a $50 bonus bet, you'll wager $50 on the underdog (NJIT) and then hedge on the favorite (Cleveland State) at another sportsbook.
Here are the outcomes:
- If NJIT at +700 wins, you'll profit $355 cash from bonus bet, but you'll lose $311.44 from the hedge, for $43.56 profit.
- If Cleveland State wins, you'll lose the bonus bet, but you'll profit $43.56.
So either way, off a $50 deposit, you've locked in a profit of $43.56, meaning you "converted" the bonus bet to cash at an 87% rate.
