MLB matchup analysis

Pirates vs Cubs Prediction, Odds and Model Pick

Saturday, September 12, 2026 at Wrigley Field · 2:20 PM ET

Value Watch

LyDia prediction: Chicago Cubs moneyline

Lab Rating
7.8/10
Model lean
Cubs 57.0%
Market probability
53.8%
Model edge
+3.2%
Best moneyline
-123
Sportsbooks checked
9
LyDia model
57.0%
Market
53.8%

The case for Chicago Cubs

Late-inning bullpen advantage
Pittsburgh Pirates relievers have a 5.46 ERA over the last 7 days; Chicago Cubs relievers have a 3.00. Pittsburgh Pirates also have 7 arms pitching on back-to-back days, against 5 for Chicago Cubs. If this is still close after six innings, that gap favors Chicago Cubs.
Bats are hot: +0.041 wOBA
Chicago Cubs is outhitting its own season form over the last 15 days. Recent form is context, not a model input, but it points the same way here.

The case for Pittsburgh Pirates

Team strength favors Pittsburgh Pirates
Before any pitcher or bullpen adjustment, LyDia's own team-strength model has Pittsburgh Pirates ahead (56.4% to 53.8%). The pick still comes from Chicago Cubs once the pitcher and bullpen terms are applied.

Why it is not official

Below the 61.0% official gate
Win probability is 57.0%. LyDia does not make a game official below 61.0%, no matter how good the price is. This is a value spot, not a high-confidence winner.

Why the setup score is what it is

Conviction: 0.99/10
LyDia leans toward Chicago Cubs, but not strongly enough to earn full conviction credit.
Pitching plan: 30.67/40
Clay Holmes rates 73 on LyDia's pitcher score, judged on its own merits (50-80 is the credited range). That is a strong start on its own, and it earns most or all of the available credit here.
Offense: 46.54/50
Chicago Cubs's recent offensive form clearly outpaces Pittsburgh Pirates's over the tracked windows.

Why the price is what it is

Team strength: 53.8%
Before any pitcher or bullpen adjustment, LyDia's team-strength model alone makes Chicago Cubs 53.8% to win. Everything below moves the price from this starting point.
Pitcher score gap: 2 points
The pitcher-score gap favors Chicago Cubs by 2 points. This is the biggest single mover of the price -- a large gap moves it a lot, a small gap barely moves it.
Bullpen adjustment: +0.123
The bullpen-fatigue gap between the two pens nudges the price toward Chicago Cubs. This moves the price less than the starting pitchers do, since a starter covers more of the game than the bullpen.
Net effect: 53.8% -> 57.0%
Team strength alone had Chicago Cubs at 53.8%. After the pitcher and bullpen terms, the price is 57.0% -- the same number shown as Model Lean above.
The verdict Real value, not an official bet. The +3.2% edge on Chicago Cubs is genuine, but below the 61.0% official gate. If you play it, you are taking on risk LyDia's official card will not.
Read the full model output

Chicago Cubs is a value watch, not an official pick. LyDia projects 57.0% against a 53.8% no-vig market number, a 3.2% model edge at -123. Lab Rating 7.8/10: conviction 0.99, pitching plan 30.67, offense 46.54. Chicago Cubs's pen efficiency: Effective (5.7/10). It stayed a value watch because model win probability is 57.0%, below the 61.0% official-pick gate. Lineup check: Chicago Cubs is swinging a hot bat (+0.105 OPS); Pittsburgh Pirates is near its season form (-0.009 OPS). Recent form supports this side and is included in the unified run projection.

Final result

Pirates 3, Cubs 4

How the analysis held up

Chicago Cubs won, the side LyDia's model favored.

Paul Skenes (No clear pitching-plan edge), the starter LyDia's pitcher score favored, actually outpitched Clay Holmes: 7.0 IP, 2 ER (2.57 ERA) against 5.2 IP, 2 ER (3.18 ERA). The edge held up.

The Pittsburgh Pirates bullpen was flagged as elevated risk pregame (High risk). In relief it actually allowed 2 earned runs over 1.0 innings (18.00 ERA) — the risk read showed up.

The Chicago Cubs bullpen was not flagged pregame, but it had a night worth noting: 0 earned runs allowed over 3.1 relief innings (0.00 ERA) — quietly better than the pregame read implied. Note: 1 of the runs charged to the Chicago Cubs pitching staff overall was unearned — not something the bullpen's stuff should be blamed for.

Game information

MatchupPittsburgh Pirates at Chicago Cubs
DateSaturday, September 12, 2026
First pitch2:20 PM ET
VenueWrigley Field
Starting pitchersPaul Skenes vs Clay Holmes
WeatherGame-time forecast: 82°F, 4% precipitation chance, 4 mph wind from W.

Starting pitcher matchup

Full Pitcher Matchup Tool →
Paul SkenesPirates · RHP
vs
Clay HolmesCubs · RHP
MetricPiratesCubs
Pitching planTraditional starterTraditional starter
Expected innings5⅓5⅔
ThrowsRR
LyDia pitcher score (higher is better)7173
ERA (lower is better)3.782.85
WHIP (lower is better)1.131.15
K/9 (higher is better)10.37.0
K-BB% (higher is better)20.9%9.8%
K% (higher is better)27.8%18.9%
BB% (lower is better)6.9%9.0%
BB/9 (lower is better)2.63.3
HR/9 (lower is better)0.90.6
Ground-ball rate44.9%65.0%
Fly-ball rate55.1%35.0%

Pitcher edge: LyDia gives Clay Holmes a 2-point edge over Paul Skenes, driven mainly by ERA (2.85 vs 3.78) and HR/9 (0.59 vs 0.94).

How to read this: the scorecards above name the starters; every number lives in this table.

Strikeout Projections Full strikeout projections →

Paul Skenes strikeouts
4.0 LyDia projected Ks
Official pick: UNDER 5.5K · -1.4K difference
Market 5.5K · O +120 / U -138 · 6 books
Clay Holmes strikeouts
4.4 LyDia projected Ks
No K play · -0.1K difference is below LyDia's 0.7K threshold
Market 4.5K · O +120 / U -135 · 6 books

Same data source as the Pitcher Matchup Tool, where every starter on the slate is compared side by side.

Pirates are 7-3 in their last 10 and averaging 4.2 runs per game over the last 15 days; Cubs are 4-6 in their last 10 and averaging 6.9 runs per game over the last 15 days. On the season Cubs carry the better run differential per game (+0.93 against +0.17).

MetricPiratesCubs
Last 107-34-6
Last 10 by venue (away team on the road, home team at home)6-4 on the road5-5 at home
OPS, last 15 days0.7230.876
wOBA, last 15 days (hot/cold read)0.3230.380
Runs per game, last 15 days4.26.9
K% last 15 days (lower is better)20.6%17.4%

Last 15 days only. Hot and cold streaks for all 30 teams live on the Stats page.

30-day offense

Full offense tool →
Last 30 daysPiratesCubs
OPS0.685 (-0.046 vs szn)0.815 (+0.044 vs szn)
Runs per game4.07 (-0.718 vs szn)5.79 (+0.443 vs szn)
wOBA (model offense input)0.306 (-0.018 vs szn)0.355 (+0.015 vs szn)
K% (lower is better)23.3% (-0.8% vs szn)19.4% (-1.9% vs szn)

Over the last 30 days the Cubs have been the better offense, 0.355 wOBA to 0.306. They are running hot against their own season line (+0.015 wOBA).

Season profile

Full Stats page →
MetricPiratesCubs
Record74-7482-66
Run differential / game (team quality)+0.17+0.93
Runs scored / game (offense, season)4.795.34
Runs allowed / game (defense, season, lower better)4.624.41
Season OPS0.7320.771
K% season (lower is better)24.0%21.3%
OPS vs opposing hand (season)0.7540.758

Season-long team quality, not recent form. Run differential and run environment come from the season standings; splits for all 30 teams live on the Stats page, including the run environment table.

Every team on today's slate, on any two axes you pick. Pirates and Cubs are highlighted.

Pirates
Combined risk
9.9 High risk
Fatigue
9.5 High risk
Efficiency
4.2 Below average
Cubs
Combined risk
5.8 Normal
Fatigue
6.1 Normal
Efficiency
5.7 Effective

Risk is what the model actually uses: fatigue blended with how well the pen has pitched. High fatigue with high efficiency is a tired pen that is still getting outs.

MetricPiratesCubs
Fatigue9.5/10, High risk6.1/10, Normal
Efficiency4.2/10, Below average5.7/10, Effective
Combined risk9.9/10, High risk5.8/10, Normal
Relief innings, last 7 days29.721.0
Back-to-back arms75
7-day ERA5.463.00
7-day WHIP1.351.33

Fatigue measures workload. Efficiency measures recent run prevention. Combined risk is what the moneyline and totals systems use.

Run total projection

Full Totals Projections →
LyDia projection
8.1
Market total
Not available
Projected away runs
2.7
Projected home runs
4.9
Over price
Not available
Under price
Not available
Pittsburgh Pirates team total
2.7 projected
Line Not available · O Not available / U Not available
Market line pending
Chicago Cubs team total
4.9 projected
Line Not available · O Not available / U Not available
Market line pending

The current model and market total cannot be compared yet. Team totals remain research-only until their graded sample is established.

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