PRA betting is betting over or under a player's combined points, rebounds and assists in one game. Bookmakers build the line by projecting each stat and adding them up, so a PRA line should sit close to the player's three main lines added together. To check a PRA price, add the fair centres of the three stats, then allow for how widely the total swings, which depends on how the three stats move together. A one-point gap between the combo line and the sum of the parts is worth roughly 5 to 7 percentage points in our worked example. That's enough to matter, but small enough that a wrong assumption can wipe it out.
The 2026-27 NBA season opened on Tuesday 20 October, with 82 games a team, so combo markets are on the board most days until April. Everything below uses invented numbers to show a method, not a view on any player or game.
NBA combo props at a glance
| Market | What it adds up | Typical use |
|---|---|---|
| PRA (P+R+A) | Points + rebounds + assists | The headline combo for most players |
| P+R | Points + rebounds | Forwards and centres |
| P+A | Points + assists | Guards who score and create |
| R+A | Rebounds + assists | Players whose value isn't scoring |
| Stocks | Steals + blocks | Defensive players, low lines |
Each one works exactly like a single-stat prop, just with a higher line because several stats are counted. All of them settle on whole numbers, so a line of 35.5 can't push: 36 or more wins the over, 35 or fewer wins the under.
How bookmakers build a PRA line
Action Network puts it plainly: sportsbooks project each individual statistic, then combine them. Its example adds a points line of 24.5, a rebounds line of 8.5 and an assists line of 9.5 to get 42.5, which matched the PRA line on offer. The same article notes there's no notable edge in blindly betting combos instead of single stats. That's the right starting point: a combo is not a better or worse bet type, only another price to check.
So the first test of any PRA line is simple arithmetic. Add the three main lines. If the PRA line is the same, or within half a point, the combo is priced in line with the parts. If it's a full point or more away, look closer.
Why the sum isn't always exact
Each main line marks the market's middle: the number the player goes over about half the time. Averages always add up. The expected value of a sum is the sum of the expected values, whether the stats are linked or not. Middles don't have to. Assists and rebounds are lopsided (a player can have 15 on a big night but never fewer than 0), and for lopsided stats the middle and the average sit slightly apart. So a PRA line half a point off the simple sum can be perfectly fair. A full point or more is where it gets interesting.
Step 1: find the fair centre of each part
Remove the margin from each main line first. If a player's points line is 22.5 at 1.90 on both sides, each side implies 52.6%, which adds up to 105.3%. Scale both back to 100% and each side is 50%, so the fair centre is 22.5. Our vig explainer covers that step, and the calculators do it in seconds.
Invented example, every side priced at 1.90:
| Stat | Main line | Fair centre |
|---|---|---|
| Points | 22.5 | 22.5 |
| Rebounds | 7.5 | 7.5 |
| Assists | 5.5 | 5.5 |
| Total | 35.5 |
If a side is lopsided, say over 7.5 rebounds at 1.80 and under at 2.00, the fair centre moves a little above 7.5. Our post on NBA alternate lines shows how to turn an uneven line into a fair centre.
Step 2: work out how widely the total swings
The centre tells you where the total sits. It doesn't tell you how much it moves from game to game, and that decides what a point is worth.
Here the maths has a useful rule: the variance of a sum is the sum of the covariances of its parts. In plain terms, the swing of the total depends on the swing of each stat and on how the stats move together. That link is the correlation, a number between -1 and +1.
- Positive correlation means the stats tend to rise and fall together. Minutes are the obvious driver: a player who plays 40 minutes has more time to collect all three than one who plays 25.
- Negative correlation means a big night in one stat tends to come with a quieter night in another, for example a game where a guard shoots a lot and passes less.
- Zero means no link, which is the easy case for the maths.
Invented example: assume a typical swing (standard deviation) of 6 points, 2.8 rebounds and 2.3 assists, and the same correlation between each pair.
| Correlation | Typical swing of PRA | As a share of the 35.5 line |
|---|---|---|
| -0.2 | 5.9 | 16.5% |
| 0 | 7.0 | 19.7% |
| +0.3 | 8.5 | 23.8% |
Two things stand out. First, the total swings far less than the three swings added together (11.1), because the stats rarely all go wrong at once. Second, relative to its size the total is steadier than points alone: 6 points on a 22.5 line is a swing of about 27%. That's why combos feel more predictable. It doesn't make them better value; it changes how much each point of line is worth.
Worked example: a PRA line one point short of the parts
Invented numbers. The three main lines add to a fair centre of 35.5. One bookmaker offers PRA over/under 34.5 at 1.90 each, a full point below the sum. Treating the total as a bell curve around 35.5, here's the fair chance of each over and its expected value at 1.90:
| PRA line | Correlation -0.2 | Correlation 0 | Correlation +0.3 |
|---|---|---|---|
| Over 34.5 | 56.8% (fair 1.76), EV +7.9% | 55.7% (fair 1.80), EV +5.8% | 54.7% (fair 1.83), EV +4.0% |
| Over 35.5 | 50.0% (fair 2.00), EV -5.0% | 50.0% (fair 2.00), EV -5.0% | 50.0% (fair 2.00), EV -5.0% |
| Over 36.5 | 43.2% (fair 2.31), EV -17.9% | 44.3% (fair 2.26), EV -15.8% | 45.3% (fair 2.21), EV -14.0% |
Expected value here is fair chance × price, minus 1.
What the table shows
- At the sum, you only pay the margin. Over 35.5 at 1.90 is -5.0% whatever the correlation, because the line sits exactly on the centre. That's the bookmaker's cut, nothing more.
- One point is worth about 5 to 7 percentage points of chance. Moving the line from 35.5 to 34.5 lifts the over from 50% to between 54.7% and 56.8%.
- The more the stats move together, the less a point is worth. A wider swing spreads the chance thinly, so the same one-point gap buys less. With strong positive correlation, the edge in this example shrinks from +7.9% to +4.0%.
- The verdict rests on the parts being right. If the rebounds line is stale, or the medians-don't-add effect is worth half a point for this player, most of the gap disappears.
A positive expected value is an estimate, and it only shows up, if at all, over many bets. Any single PRA bet can lose.
PRA over versus a multi of three overs
Some punters treat a PRA over like a same game multi of over points, over rebounds and over assists. They are very different bets.
The PRA over needs the total to clear the line. A quiet scoring night can be rescued by rebounds. A multi needs every leg to win. Using the same invented player, with each over a fair 50% chance:
| Correlation | Fair chance of all three overs | Fair price |
|---|---|---|
| -0.2 | about 7.8% | about 12.90 |
| 0 | 12.5% | 8.00 |
| +0.3 | about 19.9% | about 5.00 |
The PRA over at the sum is a 50% chance. The multi is somewhere between 8% and 20%, and where it lands depends almost entirely on the correlation, which you can't see. Our guide to the same game parlay explains why bookmakers price that linked risk into multis.
Stocks and the small combos
Stocks (steals plus blocks) are counts of 0, 1, 2 or 3 for most players, so the line is usually 0.5 or 1.5. Action Network's example had a stocks line of 1.5 with the over at -160 and the under at +120. In decimal odds that's 1.63 and 2.20, a book of about 107%, compared with 105.3% for a 1.90/1.90 line. On low counts a half-point move changes the chance a lot, and the margin tends to be bigger. Always add up both sides before you judge either one.
Checks that need no model
- Add the main lines. If the PRA line is within half a point of the sum, it's priced with the parts. A point or more away, find out why: a late injury, a stale line or a minutes change.
- Compare the same combo across bookmakers. If one book has PRA at 34.5 and another at 36.5 for the same player, the line is moving, or one book is behind. An odds screen shows the lines side by side.
- Check the margin. Add the implied chances of over and under. The higher the total above 100%, the more you're paying.
- Don't lean on short hit rates. "Over in 8 of the last 10" says little about a line that moved, as our post on NBA player prop hit rates shows.
Rules to check before you bet
- If the player doesn't play. Props on a player who never takes the court are usually void, while a player injured during the game means the bet stands. Rules differ between bookmakers, so read yours.
- Minutes drive all three stats at once. A blowout or a rest decision hits every part of a combo together, which is the positive correlation in action.
- Record the line and price you took. Comparing them with where the combo closed, your closing line value, is the honest test of whether your checks are any good.
A quick checklist
- Remove the margin from each main line to find its fair centre.
- Add the centres. Compare the total with the PRA line.
- Treat half a point either way as normal. A full point or more needs a reason.
- Think about correlation: the more the stats move together, the less a point is worth.
- Compare the same combo across bookmakers, and check the margin.
For more on the wider market, see our guide to prop betting.
See NBA combo props side by side
BetBank's NBA board shows points, rebounds, assists, threes and the combo markets across Australian bookmakers, with each line's hit rate from official results and the no-vig fair percentage where both sides are priced. That puts the three main lines and every bookmaker's PRA line on one screen, so the first check takes seconds. For the new season, first-time members on a weekly or monthly Silver or Gold plan pay half price for their first 2 months after the 7-day free trial, if they start by 30 November 2026. See how the NBA season special works.
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