An ERO (Eight Run Out) and a TR (Table Run) both recognize a run-out, but they do not have the same effect on the CompuSport Rating System (CSR).
What is the difference?
- ERO: The player pockets all their balls and the 8-ball on their first attempt, while all their object balls are still on the table.
- TR: The player clears the table on their first attempt after the opponent has already pocketed some balls.
For the definitions of each feat, see What is the difference between Table Run, ERO and Break and Run?
How does an ERO affect CSR?
An ERO uses a reference CSR of 1800. The calculation treats the performance as if you were playing against someone of that caliber.
- Winner: The calculation uses a simulated opponent rating of 1800, which can increase the CSR gain compared with a regular win against a lower-rated opponent.
- Loser: The calculation treats the winner as a player rated 1800, which can reduce the CSR loss compared with a regular loss against a lower-rated opponent.
As explained in the existing ERO article, if a player's actual CSR is above 1800, the system uses that higher rating rather than lowering it to 1800.
How does a Table Run affect CSR?
For a TR, the reference rating depends on the game score. In the 10-point scoring example below, the more points the losing player scored before the table was cleared, the lower the reference rating.
| Game score (winner–loser) | Reference CSR |
|---|---|
| 10–0 | 1800 |
| 10–1 | 1770 |
| 10–2 | 1740 |
| 10–3 | 1710 |
| 10–4 | 1680 |
| 10–5 | 1650 |
| 10–6 | 1620 |
| 10–7 | 1590 |
These numbers are simulated opponent ratings, not CSR points gained or lost. For example, 10–5 = 1650 means that the calculation uses the caliber of a 1650-rated opponent for that performance. It does not mean a player gains or loses 1650 points, or that their CSR becomes 1650.
ERO vs. TR: an example
Compare an ERO with a TR ending 10–5:
- ERO: The reference rating is 1800.
- TR at 10–5: The reference rating is 1650.
When these reference ratings raise the opponent rating used in the calculation, the ERO provides a larger adjustment: more recognition for the winner and a smaller loss for the losing player. A TR at 10–0 has the same 1800 reference as an ERO in this example.
The actual CSR change still depends on the players' ratings and the CSR calculation. The table alone does not give the final number of points gained or lost.
Why enter the correct feat?
The score alone does not explain how the game was won. Enter the correct ERO or TR, along with the correct score, so CSR can account for the run-out accurately.
Related article: Why it's important to enter ERO's.