MLB matchup analysis

Cubs vs Mariners Prediction, Odds and Model Pick

Sunday, August 23, 2026 at T-Mobile Park · 4:10 PM ET

Pass

LyDia decision: Pass on Cubs vs Mariners

Lab Rating
6.0/10
Model lean
Cubs 53.3%
Market probability
81.2%
Model edge
-27.9%
Best moneyline
-400
Sportsbooks checked
5
LyDia model
53.3%
Market
81.2%

The case for Chicago Cubs

Late-inning bullpen advantage
Seattle Mariners relievers have a 7.54 ERA over the last 7 days; Chicago Cubs relievers have a 4.13. If this is still close after six innings, that gap favors Chicago Cubs.
Bats are hot: +0.024 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 Seattle Mariners

The case is thin
The model finds little going Seattle Mariners's way — it trails on the pitching plan, bullpen, and recent form. The main path to a Seattle Mariners win is variance.

Why it is not official

Below the 61.0% official gate
Win probability is 53.3%. 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.
Setup quality below the bar
Lab Rating is 6.0/10, under the 7.2/10 required for an official pick.
Own bullpen carries risk: 6.5/10
The Chicago Cubs bullpen comes in tired. A lead after six innings is less safe than usual.

Why the setup score is what it is

Conviction: 0/10
LyDia's own win probability for Chicago Cubs (53.3%) is close enough to a coin flip that the rating credits little or no conviction -- credit only starts above 55%.
Pitching plan: 0/20
No meaningful starting-pitcher edge favors Chicago Cubs in this matchup.
Bullpen: 13.41/20
Chicago Cubs's bullpen carries a real edge over Seattle Mariners's tonight.
Offense: 46.81/50
Chicago Cubs's recent offensive form clearly outpaces Seattle Mariners's over the tracked windows.

Why the price is what it is

Team strength: 50.2%
Before any pitcher or bullpen adjustment, LyDia's team-strength model alone makes Chicago Cubs 50.2% to win. Everything below moves the price from this starting point.
Pitcher score gap: 1 points
The pitcher-score gap favors Chicago Cubs by 1 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: +0.054
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: 50.2% -> 53.3%
Team strength alone had Chicago Cubs at 50.2%. After the pitcher and bullpen terms, the price is 53.3% -- the same number shown as Model Lean above.
The verdict LyDia passes. The combined Lab Rating did not clear the official threshold.
Read the full model output

The combined Lab Rating did not clear the official threshold.

Final result

Cubs 19, Mariners 2

How the analysis held up

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

Bryce Miller (No clear pitching-plan edge) was LyDia's favored starter by pitcher score, but Shota Imanaga actually pitched better tonight: 2.0 IP, 1 ER (4.50 ERA) against 4.1 IP, 6 ER (12.46 ERA). The edge did not show up in this game.

The Chicago Cubs bullpen was not flagged pregame, but it had a night worth noting: 0 earned runs allowed over 7.0 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.

The Seattle Mariners bullpen was flagged as elevated risk pregame (High risk). In relief it actually allowed 13 earned runs over 4.2 innings (25.07 ERA) — the risk read showed up.

Chicago Cubs scored 19, 12.7 more than the 6.3 pregame projection.

Seattle Mariners scored 2, 1.6 fewer than the 3.6 pregame projection.

Game information

MatchupChicago Cubs at Seattle Mariners
DateSunday, August 23, 2026
First pitch4:10 PM ET
VenueT-Mobile Park
Starting pitchersShota Imanaga vs Bryce Miller
WeatherGame-time forecast: 71°F, 1% precipitation chance, 4 mph wind from NW. This venue has a roof, but the roof status is not confirmed.

Starting pitcher matchup

Full Pitcher Matchup Tool →
Shota ImanagaCubs · LHP
vs
Bryce MillerMariners · RHP
MetricCubsMariners
Pitching planTraditional starterTraditional starter
Expected innings5⅔5⅔
ThrowsLR
LyDia pitcher score (higher is better)7169
ERA (lower is better)3.784.12
WHIP (lower is better)1.121.09
K/9 (higher is better)8.98.8
K-BB% (higher is better)18.6%17.8%
K% (higher is better)24.3%24.5%
BB% (lower is better)5.7%6.6%
BB/9 (lower is better)2.12.4
HR/9 (lower is better)1.91.6
Ground-ball rate39.8%40.9%
Fly-ball rate60.2%59.1%

Pitcher edge: LyDia gives Shota Imanaga a 2-point edge over Bryce Miller, driven mainly by BB/9 (2.1 vs 2.4) and ERA (3.78 vs 4.12).

How to read this: the scorecards above name the starters; every number lives in this table. Highlighted cells mark a gap big enough to matter. K% and BB% are strikeout and walk rate as a share of batters faced -- K-BB% is the two combined into one skill number. HR/9 is home runs allowed per nine innings. Ground-ball and fly-ball rate are neither good nor bad on their own: high ground-ball pitchers trade strikeouts for double plays and fewer home runs, and on this data source the two rates are complementary (they add to 100%), not independent reads.

Strikeout Projections Full strikeout projections →

Shota Imanaga strikeouts
5.2 LyDia projected Ks
No K play · -0.3K difference is below LyDia's 0.7K threshold
Market 5.5K · O -108 / U -106 · 6 books
Bryce Miller strikeouts
4.7 LyDia projected Ks
Official pick: UNDER 5.5K · -1.1K difference
Market 5.5K · O +132 / U -165 · 6 books

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

Cubs are 4-6 in their last 10, averaging 5.9 runs per game over the last 15 days, and swinging above their season form; Mariners are 6-4 in their last 10 and averaging 3.9 runs per game over the last 15 days. On the season Cubs carry the better run differential per game (+0.88 against -0.47).

MetricCubsMariners
Last 104-66-4
Last 10 by venue (away team on the road, home team at home)6-4 on the road4-6 at home
OPS, last 15 days0.8320.681
wOBA, last 15 days (hot/cold read)0.3600.304
Runs per game, last 15 days5.93.9
K% last 15 days (lower is better)22.4%23.6%

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 daysCubsMariners
OPS0.800 (+0.038 vs szn)0.673 (-0.011 vs szn)
Runs per game5.66 (+0.434 vs szn)3.50 (-0.416 vs szn)
wOBA (model offense input)0.349 (+0.013 vs szn)0.300
K% (lower is better)22.6% (+0.8% vs szn)23.4%

Over the last 30 days the Cubs have been the better offense, 0.349 wOBA to 0.300. They are running hot against their own season line (+0.013 wOBA).

Season profile

Full Stats page →
MetricCubsMariners
Record75-5662-69
Run differential / game (team quality)+0.88-0.47
Runs scored / game (offense, season)5.223.92
Runs allowed / game (defense, season, lower better)4.344.38
Season OPS0.7620.684
K% season (lower is better)21.8%23.0%
OPS vs opposing hand (season)0.7450.643

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. Cubs and Mariners are highlighted.

Cubs
Combined risk
6.5 Tired
Fatigue
6.4 Tired
Efficiency
4.8 Average
Mariners
Combined risk
8.3 High risk
Fatigue
6.9 Tired
Efficiency
2.3 Struggling

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.

MetricCubsMariners
Fatigue6.4/10, Tired6.9/10, Tired
Efficiency4.8/10, Average2.3/10, Struggling
Combined risk6.5/10, Tired8.3/10, High risk
Relief innings, last 7 days24.022.7
Back-to-back arms45
7-day ERA4.137.54
7-day WHIP1.461.76

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
10.4
Market total
11.5
Projected away runs
6.3
Projected home runs
3.6
Over price
-121
Under price
+105
Chicago Cubs team total
6.3 projected
Line 7.5 · O +125 / U -115
Under research lean (-1.2)
Seattle Mariners team total
3.6 projected
Line 4.5 · O +124 / U -142
Under research lean (-0.9)

The model projects 1.1 runs below the market total. A research lean still requires a setup rating of at least 7.0/10. Team totals remain research-only until their graded sample is established.

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