New Markets: BTTS and OU25 Side-Select — Adding 750 Bets/Year
Tested BTTS and OU25 per-league × per-side × per-season. 38 combinations tested, 3 stable: Segunda BTTS Yes (+7.5%), Bundesliga 2 OU25 Under (+2.0%), Belgian Pro OU25 Under (+8.8%). Year-over-year stability check caught EPL BTTS Yes and Championship BTTS No as unstable (1/3 years). ~360 additional bets/year deployed.
New Markets: BTTS and OU25 Side-Select — Adding 750 Bets/Year
The model has been AH-only. That's where the money is — +6.5% CLV, +2.49% historical ROI, +27.5% live ROI. But AH gives us ~1,000 bets per year. The Fundamental Law of Active Management says: IR = IC × √BR. Same skill, more bets, better information ratio.
BTTS and OU25 were sitting right there in the score grid. We just hadn't tested whether they're profitable.
The Question
Can we add BTTS (Both Teams To Score) and OU25 (Over/Under 2.5) as new betting markets? Not blindly — per-league, per-side, with year-over-year stability validation.
What We Found
BTTS: 7,412 bets across 19 leagues
Overall: CLV +9.5%, ROI -5.96%. Negative at scale — like OU25, the model finds value but can't convert it profitably across all leagues.
But the per-league × per-side breakdown reveals structure:
| League | BTTS Yes ROI | BTTS No ROI | Best Side |
|---|---|---|---|
| Segunda | **+7.5%** (229) | -15.3% (87) | Yes |
| Championship | +0.9% (142) | **+4.1%** (296) | No |
| EPL | **+8.9%** (138) | -2.0% (155) | Yes |
| Serie A | -6.7% (157) | -20.3% (177) | Neither |
| Eredivisie | -20.1% (42) | -16.2% (309) | Neither |
The profitable side varies by league. Championship's "No" edge means the model correctly identifies clean sheet opportunities. Segunda/EPL "Yes" means both teams scoring more than the market expects.
Year-over-year stability check (the critical gate):
| Signal | 2022-23 | 2023-24 | 2024-25 | Stable? |
|---|---|---|---|---|
| Segunda Yes | +19% | -1% | +13% | **Yes (2/3)** |
| EPL Yes | -10% | +20% | -2% | No (1/3) |
| Championship No | -4% | +13% | -3% | No (1/3) |
Only Segunda BTTS Yes is stable. EPL and Championship flip-flop. We almost deployed both — the year-over-year check caught it.
OU25: Same analysis, per-side
| League + Side | 2022-23 | 2023-24 | 2024-25 | Stable? |
|---|---|---|---|---|
| Bundesliga 2 Under | +6% | +6% | 0% | **Yes (3/3)** |
| Belgian Pro Under | -12% | +7% | +10% | **Yes (2/3)** |
| La Liga Under | -11% | +9% | -6% | No (1/3) |
| Championship Under | +4% | -9% | +10% | Mixed |
| Ligue 2 Over | -8% | +6% | -8% | No (1/3) |
Bundesliga 2 Under is rock solid — positive in all 3 tested seasons. Belgian Pro Under is improving and passed 2/3.
The Nuance
Why does the profitable side vary by league?
The model over-predicts goals by 8.7% on average. But this varies:
- In Championship: the model OVER-predicts goals → "Under" is the correction side → BTTS No benefits (fewer goals = fewer both-score outcomes)
- In Segunda: the model correctly identifies attacking imbalances → "Yes" edge is genuine
Why the stability check matters:
EPL BTTS Yes looked amazing: +8.9% ROI, 138 OOS bets, 64.5% hit rate. But one year earlier it was -10%. And one year later -2%. The aggregate OOS number was driven by one exceptional season (2023-24: +20%). Without the year-over-year check, we would have deployed a signal that's profitable 1-in-3 years.
What Didn't Work
Every league × side combination that showed the OPPOSITE pattern from our hypothesis:
- Serie A BTTS: both sides negative, both unstable
- Turkish Super: BTTS No -26.4% (worst in dataset)
- Eredivisie: BTTS Yes -20.1%
- Scottish Prem: both sides -11% to -17%
These leagues' BTTS markets are either efficiently priced or our model is structurally wrong for these specific prediction types in these contexts. We don't know which — and we don't need to. The data says don't bet.
What This Means
Deployed (stable across seasons):
| Signal | League | Side | Est. Bets/Year | OOS ROI |
|---|---|---|---|---|
| BTTS | Segunda | Yes | ~100 | +7.5% |
| OU25 | Bundesliga 2 | Under | ~100 | +2.0% |
| OU25 | Belgian Pro | Under | ~160 | +8.8% |
Total: ~360 additional bets/year. Combined with ~1,000 AH bets, that's a 36% increase in breadth.
At $20/bet flat staking:
- Segunda BTTS Yes: ~$150/year
- Bundesliga 2 Under: ~$40/year
- Belgian Pro Under: ~$280/year
- Total: ~$470/year incremental
This isn't transformative by itself, but it's free — the model already computes these probabilities on every prediction. No new modeling required.
What's Next
- Monitor live performance — these signals are deployed, logging to paper trade. Watch for 50+ settled bets per signal.
- Phase 3: More leagues — FootyStats covers 1,500+ leagues. Each new league with positive AH CLV adds to the portfolio. The side-select framework applies to all of them.
- Combined portfolio test — pre-registered as
btts-ou25-combined-portfolio. Need to validate that adding BTTS + OU25 doesn't degrade AH Sharpe via correlation. - Re-evaluate unstable signals annually — EPL BTTS Yes and Championship BTTS No may stabilize with more data. Re-test after 2025-26 season completes.