NBA Moneyline Betting — When to Back Favourites and When to Take the Underdog

The moneyline is the simplest NBA bet — pick the winner. No spread, no total, just who wins the game.

Simple in theory. Harder in practice.

How moneyline odds work

Each team is given odds based on their probability of winning. The favourite gets short odds — you risk more to win less. The underdog gets long odds — you risk less to win more.

In decimal format you'll see something like:

• Boston Celtics: 1.35

• Philadelphia 76ers: 3.20

Boston are heavy favourites. A £10 bet on Boston returns £13.50 total — £3.50 profit. A £10 bet on Philadelphia returns £32 total — £22 profit if they pull off the upset.

Implied probability

The odds imply a probability. To convert decimal odds to implied probability, divide 1 by the odds.

Boston at 1.35 implies a 74% win probability (1 ÷ 1.35 = 0.74). Philadelphia at 3.20 implies a 31% win probability (1 ÷ 3.20 = 0.31).

Those add up to more than 100% — the extra percentage is the bookmaker's margin, also called the vig or juice.

When is moneyline value worth taking?

The moneyline is only worth betting when your model's win probability is higher than the implied probability in the odds.

If the HMJOROTips model gives Boston a 80% win probability but the bookmaker's odds imply only 74%, that's a 6% edge — the model thinks Boston are more likely to win than the bookmaker does.

If the model gives Boston 70% but the odds imply 74%, there's no value — you'd be paying over the odds for a bet the model thinks is worse than the bookmaker's price.

Favourites vs underdogs

Heavy favourites — teams priced at 1.20 or below — offer very little value on the moneyline even when they're likely to win. You're risking a lot to win a little, and one upset wipes out multiple wins.

The interesting moneyline value tends to be in the 1.50 to 2.20 range — teams that are favourites but not overwhelming ones, or strong underdogs in genuinely competitive games.

In the NBA, upsets happen regularly. The best team in the league loses roughly 15-20% of their regular season games. In the playoffs that rate drops, but it never goes to zero.

Moneyline vs spread

For games with big spreads — say -9 or more — the spread is almost always better value than the moneyline. The favourite winning by 9+ is harder to achieve than just winning, and you get significantly better odds on the spread.

For close games with small spreads — say -2 or -3 — the moneyline can be cleaner. You're paying a small premium to not have to worry about covering the spread.

The model shows both the ML pick and the spread pick separately. They won't always agree — sometimes there's value in backing a team to win but not to cover a large spread.