← Back to dashboard
Mark Mathews
Tipster dossier — settled-bet performance through 2026-07-14 20:15 UTC
Verdict
ROI MISLEADING
Calibration is negative: actual win rate 24.7% trails market-implied 27.8% by -3.1pp — picks have negative skill relative to fair odds. 81% of total P/L comes from just the top 2 winning tips. Strip them out and you'd see an ROI of +6.6% on 91 bets — the headline number is being held up by a couple of lucky longshots. Recent 30d (ROI -68.2%) is materially worse than the prior 60d (+111.6%) — trend is declining. Bayesian-shrunk ROI (regressed toward -13% population baseline by sample size) is +17.7% — a more honest expectation than the raw +34.2%.
Bio & context
Mark Mathews is primarily a Tabcorp/Sky Racing race caller based in Adelaide, South Australia, who also provides occasional racing tips published on platforms like The Great Tip Off. He became a full-time race caller in December 2022 after 10 years of calling races part-time while maintaining a corporate career in sales and account management (including roles at Arnott's and Michelin). His tipping appears to be a secondary activity to his main role as a multi-code race caller (gallops, greyhounds, and harness).
Adelaide, South AustraliaRace Caller (Tabcorp/Sky Racing) - occasional tipster12 yrs
⚠ Conflict / insider flags
- Primary role is race caller for Tabcorp/Sky Racing - potential institutional conflict
- Tips South Australian racing where he actively calls races - deep local knowledge but potential for bias toward familiar connections
Methodology: Not publicly disclosed. Tips appear on Sky Racing/The Great Tip Off platform but no detailed methodology information available.
Specialty: South Australian racing - particularly country tracks including Morphettville, Strathalbyn, Mount Gambier, Port Lincoln, Naracoorte
Public footprint
- Twitter: @MarkRaceCalling (joined August 2017, minimal activity)
- Sky Racing broadcaster - calls races across all codes
- Tips published on The Great Tip Off platform (SKY Racing | SA)
- Featured in Country Racing SA interview (May 2023)
Source: anthropic_web_search · last researched 2026-06-10
Since last weekly snapshot: +3 new bets · ROI: -0.6% (+34.8% → +34.2%) · Shrunk ROI: —
Charts
Cumulative P/L (theoretical $1 stakes)
A straight upward line = consistent profitability. Step-jumps = single fortunate bets carrying the curve.
Monthly ROI %
Top 10 P/L outliers
ROI by odds bracket
Calibration — actual vs implied win rate by odds
Blue bars under orange = picks lose to market expectations.
ROI by day of week
At a glance
Total P/L ($1 stakes)
+$31.85
Bayesian-shrunk ROI
+17.7%
Implied Win % (1/odds)
27.8%
What's driving the ROI?
Strip away the top winning bets and see how the picture changes — a stable record degrades gracefully,
a lucky record collapses.
| Subset | N | P/L | ROI |
|---|
| Full record | 93 | +$31.85 | +34.2% |
| Minus best 1 bet | 92 | +$18.95 | +20.6% |
| Minus best 2 bets | 91 | +$6.05 | +6.6% |
| Minus best 5 bets | 88 | $-25.15 | -28.6% |
If stripping the top 2 wins materially changes the ROI, the headline number is being held up by a couple of fortunate longshots — not stable skill.
Recent trend
Monthly performance
| Month | N | Win % | Avg Odds | P/L | ROI |
|---|
| 2026-04 | 13 | 23.1% | 4.48 | $-2.30 | -17.7% |
| 2026-05 | 33 | 33.3% | 5.10 | +$49.45 | +149.8% |
| 2026-06 | 21 | 23.8% | 4.41 | $-0.25 | -1.2% |
| 2026-07 | 26 | 15.4% | 4.76 | $-15.05 | -57.9% |
By odds bracket
| Odds | N | Win % | P/L | ROI |
|---|
| <2.0 | 9 | 33.3% | $-8.10 | -90.0% |
| 2.0-3.0 | 17 | 29.4% | $-2.95 | -17.4% |
| 3.0-5.0 | 38 | 28.9% | +$47.90 | +126.1% |
| 5.0-8.0 | 17 | 23.5% | +$7.00 | +41.2% |
| 8.0-15 | 11 | 0.0% | $-11.00 | -100.0% |
| 15+ | 1 | 0.0% | $-1.00 | -100.0% |
By pre-race rank
| Pre-race Rank | N | Win % | P/L | ROI |
|---|
| Rank 1 (fav) | 28 | 25.0% | $-9.95 | -35.5% |
| Rank 2 | 16 | 25.0% | +$18.50 | +115.6% |
| Rank 3 | 6 | 50.0% | +$11.30 | +188.3% |
| Rank 4-5 | 10 | 10.0% | $-3.50 | -35.0% |
| Rank 6+ | 3 | 0.0% | $-3.00 | -100.0% |
Based on 63 of 93 tips where pre-race rank was captured live (data started May 17, 2026).
Strategy Zone (rank ≤ 3 AND odds ≥ 5)
| Subset | N | Win % | P/L | ROI |
|---|
| In Zone (rank ≤ 3 AND odds ≥ 5) | 10 | 30.0% | +$7.50 | +75.0% |
| Outside Zone | 53 | 22.6% | +$5.85 | +11.0% |
By source
| Source | N | Win % | P/L | ROI |
|---|
| racing_com | 93 | 24.7% | +$31.85 | +34.2% |
By venue
Top venues (by total P/L)
| Venue | N | Win % | P/L | ROI |
|---|
| mount gambier | 9 | 44.4% | +$27.70 | +307.8% |
| morphettville parks | 18 | 27.8% | +$21.60 | +120.0% |
| port augusta | 14 | 42.9% | +$11.80 | +84.3% |
| sportsbet gawler | 13 | 23.1% | $-1.15 | -8.8% |
| morphettville | 8 | 12.5% | $-5.00 | -62.5% |
| thomas farms rc murray bridge | 16 | 18.8% | $-11.10 | -69.4% |
| bordertown | 15 | 6.7% | $-12.00 | -80.0% |
By day of week
| Day | N | Win % | P/L | ROI |
|---|
| Wed | 16 | 18.8% | $-5.05 | -31.6% |
| Fri | 24 | 25.0% | +$19.60 | +81.7% |
| Sat | 33 | 24.2% | +$11.50 | +34.8% |
| Sun | 20 | 30.0% | +$5.80 | +29.0% |
Place market
Live place-capture data: 6 settled, place rate 66.7%.
Hypothetical $1 place-bet P/L at captured Betfair BSP: +$3.79 (+63.2% ROI) on 6 bets.
Place data started May 17, 2026. Sample size small — treat directionally only.
Biggest wins
| Date | Venue | Selection | Odds | P/L |
| 2026-05-16 | morphettville parks | Invertational | 4.80 | +$12.90 |
| 2026-05-16 | morphettville parks | Royal Sway | 4.80 | +$12.90 |
| 2026-05-22 | mount gambier | Supreme Thunder | 4.80 | +$12.00 |
| 2026-05-22 | mount gambier | Giddy Up Bankcheck | 4.20 | +$11.10 |
| 2026-05-22 | mount gambier | Naralinga | 4.00 | +$8.10 |
Biggest losses
| Date | Venue | Selection | Odds | P/L |
| 2026-05-22 | mount gambier | Del Lirenza | 1.95 | $-3.00 |
| 2026-05-22 | mount gambier | The Narrator | 1.90 | $-3.00 |
| 2026-05-16 | morphettville parks | Grinzinger Halo | 2.70 | $-3.00 |
| 2026-05-16 | morphettville parks | Romans Luck | 2.60 | $-3.00 |
| 2026-05-27 | sportsbet gawler | Miss Sghirripa | 3.70 | $-1.00 |
Generated 2026-07-14 20:15 UTC. Stats based on theoretical $1 BACK stakes settled on Betfair. Place data uses captured Betfair Starting Price.
ROI = total P/L divided by total bets — high variance at small samples.