Fair Odds for Player Props: How JOPP Builds Them and How to Compare Kambi and Bet365

A fair odd is the price a bet would have if nobody took a cut. It's simply 1 divided by the true probability of the outcome:

fair odd = 1 / probability

If a player has a 25% chance of scoring, his fair odd is 4.00. At 4.00 you'd break even over the long run. Anything above 4.00 pays you more than the bet is worth, anything below pays you less.

The catch is the word "true". Nobody knows the true probability, so every fair odd is an estimate. The question is where your estimate comes from.

For two-way or three-way markets, the usual way to get a fair odd is to remove the bookmaker margin from the price. I walk through that in implied probability and bookmaker margin.

It only works when you can see every outcome. Most player props don't give you that:

• Anytime goalscorer usually only has a "yes" price. You can't tell how much of it is margin.
• Adding up every player's goalscorer price doesn't give you a clean 100% either, because several players can score in the same match and sometimes nobody does.
• Shots and shots on target are sometimes offered as over and under, but often only as 1+, 2+ and 3+ lines with one side.

So for most player markets, the honest way to get a fair odd is to build it yourself from player data. That's what a model does.

For every player in every fixture, JOPP's statistical model estimates how likely he is to score, assist or hit a shots line. It works from four things:

1. His own recent form in that market.
2. The opposition, because a striker facing a team that concedes a lot of chances is a different bet from the same striker facing a tight defence.
3. The home or away split, since plenty of players produce noticeably more at home.
4. How many minutes he's expected to play.

That probability becomes the fair odd. The landing page uses this illustration: a player with a 31% chance of scoring has a fair odd of 1 / 0.31, about 3.23.

Why expected minutes matter so much#

Expected minutes are the part people most often get wrong when they price props by hand. A player who averages a goal every three matches when he plays 90 minutes is a much worse bet if he's likely to come off after an hour, or if he's rotated in midweek.

JOPP builds expected minutes into each fair odd, so the price is already per match. You don't have to take a per 90 number and rescale it yourself. If you want to understand what moves those minutes, confirmed lineups betting covers team news, rotation and position changes.

The penalty toggle#

Penalties change goalscorer prices a lot, and they're not spread evenly: one player in the team takes them. JOPP has a penalty toggle that recalculates the fair odd for the designated taker. If you know who's on penalties for that match, switch it on and compare again.

Once you have a fair odd, the comparison is one formula:

EV% = (bookmaker odd / fair odd - 1) x 100

Using the same illustration from the landing page: fair odd 3.23, bookmaker odd 3.80.

3.80 / 3.23 - 1 = about 0.176, so EV is +17.6%. The bookmaker is paying 17.6% more than the model thinks the bet is worth.

If the bookmaker had offered 3.00 instead, EV would be 3.00 / 3.23 - 1, about -7.1%. Same player, same match, but now you're paying for the privilege. The full logic behind EV is in what is expected value in betting, and you can run your own numbers in the EV calculator.

Why compare two bookmakers, not one#

JOPP reads Kambi and Bet365 prices automatically every 15 minutes and puts them in the same row as the fair odd. Kambi is the odds supplier behind Unibet, 888sport and other Kambi-powered books, so one Kambi price tells you what several bookmakers are offering. Bet365 sets its own prices.

Having both next to the fair odd helps in three ways:

• You see where the value is. Often one source is above the fair odd and the other isn't. That's the price to take.
• You see how strong the signal is. If both bookmakers sit well above the fair odd, it's worth asking whether the model is missing something, like late team news. If only one is, it's more likely that one book is simply out of line.
• You know how fresh the prices are. The header shows when each source was last updated, so you're not comparing a fair odd with a price that has already moved.

I go deeper into how B2B suppliers like Kambi set their numbers in how bookmakers price player props.

This is roughly how I use it before a match day:

1. Start with Value Bets. It's one ranked list of every price above its fair odd. Filter by market, bookmaker, league, date or minimum EV.
2. Click the EV% to open the history. It shows how often that market landed for the player, with filters for season, starts, home or away and competition. If the history and the price tell very different stories, find out why before you bet.
3. Check the team news. A fair odd assumes the expected minutes. If the player is benched or rested, the bet is a different bet.
4. Check the rules. Bookmakers settle player markets differently, for example on non-starters. Bet365's player markets are void if the player doesn't start, but check your own bookmaker's rules for the market you're betting.
5. Track what you take. In My Bets you star the bet, add the price and units, and it settles automatically from the match data with ROI, hit rate and a profit curve.

JOPP has fair odds for seven player markets: goals, assists, goal or assist, shots, shots on target, headers and outside the box. Each has its own rules, so it's worth reading the guide before you bet one you don't know well:

• Anytime goalscorer bets explained
• Shots on target betting and player shots bets explained
• Assist bets explained and goal or assist bets
• Headers and outside the box bets

• Treating a fair odd as a fact. It's an estimate. A model can't know about an injury in the warm-up or a tactical change nobody announced.
• Expecting positive EV to win every time. A +15% bet at 4.00 still loses most of the time. EV is a long-run average, and with props the swings are big. That's why bankroll management matters.
• Comparing a fair odd with a stale price. Prices move, especially after lineups. Always check how fresh the bookmaker price is.
• Ignoring margin in bet builders. Every leg carries its own margin, so combining props can wipe out the value of each one. See bet builder tips.
• Forgetting the minutes. A per 90 hit rate is not a per match probability. A fair odd has to account for how long the player is on the pitch.