Matchup analysis
Before kickoff our model projected Illinois State 28.6, South Dakota State 27 at Hancock Stadium in Week 5. That is a genuine toss-up: Illinois State wins about 54% of the time by our estimate, with a projected margin of 1.6 points and 55.6 combined points. Tags: coin flip.
South Dakota State is 4-1, scoring 42.8 and allowing 16.4 points per game (+26.4 per game). Illinois State is 4-1, scoring 43 and allowing 15 points per game (+28 per game).
College football is noisy: even a well-rated projection misses the final margin by about 14 points on average. Based on how real results have scattered around our numbers, the final margin should land somewhere between South Dakota State by 21 and Illinois State by 24 about 80% of the time.
Illinois State gets about 2.1 points for playing at home. That home edge is the difference: on a neutral field South Dakota State would be favoured by 0.5. The game is on ESPN+.
Result: South Dakota State 31, Illinois State 14. South Dakota State won, so this goes down as a miss for the model (margin off by 18.6 points).
Market lines
Market lines · Source: The Odds API, ESPN, Action Network · Updated Oct 29, 9:25 AM UTC. Shown for information; not an input to our projections.
| Provider | Spread (open → now) | Total (open → now) | Moneyline (South Dakota State / Illinois State) |
|---|---|---|---|
| Consensus | South Dakota State -1.5 → South Dakota State -2.5 | 55.5 → 51.5 | -127 / +102 |
| DraftKings | South Dakota State -1.5 → South Dakota State -2.5 | 55.5 → 51.5 | -127 / +102 |
This game's lines: CollegeFootballData.com · read Oct 22, 6:37 PM UTC.
| Projection | Margin | Total | Illinois State win |
|---|---|---|---|
| Our model | Illinois State -1.5 | 55.6 | 54% |
| Market consensus | South Dakota State -2.5 | 51.5 | 47% |
| Blended projection | South Dakota State -2 | 52.4 | 45% |
Blended projection = 0.16 x our margin + 0.84 x the market margin, weights fitted on past seasons (see methodology).
Model vs market
- Illinois State win probability
- model 54% · market (no-vig) 47% · difference +7 pts
- Margin
- model Illinois State -1.6 · market South Dakota State -2.5 · difference +4.1 pts (Illinois State view)
- Total
- model 55.6 · market 51.5 · difference +4.1
Model margin is 4.1 pts more toward Illinois State than the market.
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Original projection vs new formula
| Projection | Score | Win prob | Margin miss | Total miss |
|---|---|---|---|---|
| Original projection | South Dakota State 27.0, Illinois State 28.6 | Illinois State 54%wrong winner | 18.6 | 10.6 |
| New formula | South Dakota State 26.4, Illinois State 28.9 | Illinois State 56%wrong winner | 19.5 | 10.3 |
Final: South Dakota State 31, Illinois State 14. Original = the number we posted before kickoff. New formula (2026-10-21 matchup terms) = the current model re-run with only the games played before this one.
South Dakota State vs Illinois State: stat comparison
2025 season numbers (this season's sample is still too small).
| Stat | South Dakota State | Illinois State |
|---|---|---|
| Points per game | 28.6 | 30.8 |
| Points allowed per game | 21.9 | 25.7 |
| Yards per play | 5.56 | 5.89 |
| Yards per play allowed | 5.21 | 5.91 |
| Rushing yards per game | 169.6 | 171.5 |
| Net passing yards per game | 212.8 | 229.5 |
| Rushing yards allowed per game | 132.3 | 144.4 |
| Net passing yards allowed per game | 184.8 | 236.4 |
| Turnovers per game | 1.25 | 1.00 |
| Takeaways per game | 1.25 | 1.35 |
| Sacks per game | 1.92 | 2.00 |
| Sacks allowed per game | 2.25 | 1.06 |
| Stat | South Dakota State | Illinois State |
|---|---|---|
| EPA per play | +0.05 | +0.06 |
| EPA per play allowed | -0.11 | +0.06 |
| Success rate | 43.5% | 45.7% |
| Success rate allowed | 40.4% | 42.9% |
| Explosive play rate | 11.4% | 12.0% |
| Explosive plays allowed | 10.8% | 12.3% |
| Havoc rate | 14.8% | 14.1% |
| Havoc allowed | 14.2% | 9.2% |
| Points per scoring opportunity | 0.87 | 1.27 |
| Points per opportunity allowed | 0.54 | 1.54 |
| Average starting field position | opp 0 | opp 4 |
| Opponents' starting field position | opp 0 | opp 5 |
| Offensive plays per game (pace) | 68.8 | 68.1 |
| Stat | South Dakota State | Illinois State |
|---|---|---|
| Rushing EPA per play | +0.05 | +0.01 |
| Passing EPA per play | +0.05 | +0.11 |
| Rushing EPA allowed | -0.10 | +0.03 |
| Passing EPA allowed | -0.11 | +0.09 |
| Rushing success rate | 43.7% | 45.6% |
| Passing success rate | 43.8% | 45.8% |
| Run stuff rate | 18.1% | 15.8% |
| Passing-down success rate | 35.3% | 36.2% |
| Passing-down success allowed | 28.5% | 31.2% |
| Third-down conversion rate | 42.7% | 45.7% |
| Third-down rate allowed | 32.9% | 40.9% |
| Red-zone touchdown rate | 13.7% | 19.3% |
| Red-zone TD rate allowed | 8.9% | 23.9% |
# = rank among 136 FBS teams. Efficiency numbers exclude garbage time. Per-play numbers of teams with a weak schedule are pulled toward their opponent-adjusted values (fully at one standard deviation below an average schedule). Source: play-by-play (cfbfastR / sportsdataverse), aggregated by us.
More: South Dakota State schedule · Illinois State schedule · all Week 5 projections
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Projections are statistical estimates for entertainment and analysis only. They are not betting advice and nothing here guarantees any result.
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