Every upcoming MLB fixture on Polymarket and every forecastable market on it — the whole board, uncapped. Keyless, live, cached a few minutes. A market is tradeable when its spread is ≤ 5¢ and ≥ $100 sits within 2¢ of the ask.
Every resolved MLBmarket the favorite-longshot backtest could reconstruct point-in-time from Polymarket's price history: 10,213 markets across 361 fixtures. The question is whether the market itself is mispriced — buy every favorite and win. It isn't, and you don't.
Calibration — is the price the probability?
Each bucket: what the market charged, versus how often it actually happened. The gap averages 0.70c — the price is the probability.
market price
n
actually won
gap
0.085
26
0.154
+0.069
0.159
1,265
0.173
+0.014
0.248
2,114
0.258
+0.010
0.399
4,303
0.403
+0.003
0.578
1,827
0.586
+0.008
0.755
674
0.760
+0.005
Everything here is generated from public market data and provided for information only. It is not betting advice, not a recommendation to wager, and not a claim that any edge exists. Live prices move; the snapshot is minutes old by the time you read it.
1¢
$31.1k
tradeable
SpreadSpread -2.5
28¢ / 30¢
2¢
$17.4k
tradeable
SpreadSpread -1.5
39¢ / 40¢
1¢
$29.6k
tradeable
SpreadSpread -1.5
33¢ / 34¢
1¢
$16.0k
tradeable
SpreadSpread -2.5
24¢ / 25¢
1¢
$1.1k
tradeable
1¢
$5.5k
tradeable
SpreadSpread -1.5
36¢ / 37¢
1¢
$29.5k
tradeable
SpreadSpread -1.5
33¢ / 34¢
1¢
$18.2k
tradeable
SpreadSpread -2.5
23¢ / 24¢
1¢
$14.3k
tradeable
SpreadSpread -2.5
25¢ / 26¢
1¢
$2.3k
tradeable
1¢
$14.0k
tradeable
SpreadSpread -1.5
36¢ / 37¢
1¢
$21.3k
tradeable
SpreadSpread -2.5
25¢ / 26¢
1¢
$14.0k
tradeable
SpreadSpread -1.5
34¢ / 36¢
2¢
$18.8k
tradeable
SpreadSpread -2.5
25¢ / 28¢
3¢
$4.2k
tradeable
tradeable
TotalsO/U 8.5
60¢ / 61¢
1¢
$7.1k
tradeable
TotalsO/U 10.5
43¢ / 44¢
1¢
$9.8k
tradeable
SpreadSpread -2.5
22¢ / 24¢
2¢
$5.0k
tradeable
SpreadSpread -1.5
41¢ / 42¢
1¢
$40.0k
tradeable
SpreadSpread -1.5
32¢ / 33¢
1¢
$15.8k
tradeable
SpreadSpread -2.5
31¢ / 33¢
2¢
$19.4k
tradeable
$17.2k
tradeable
TotalsO/U 7.5
44¢ / 45¢
1¢
$25.5k
tradeable
TotalsO/U 8.5
36¢ / 37¢
1¢
$13.9k
tradeable
SpreadSpread -1.5
35¢ / 36¢
1¢
$31.9k
tradeable
SpreadSpread -2.5
24¢ / 26¢
2¢
$17.8k
tradeable
SpreadSpread -1.5
32¢ / 33¢
1¢
$11.2k
tradeable
SpreadSpread -2.5
22¢ / 24¢
2¢
$4.9k
tradeable
1¢
$28.5k
tradeable
TotalsO/U 8.5
60¢ / 61¢
1¢
$4.4k
tradeable
TotalsO/U 10.5
45¢ / 46¢
1¢
$23.1k
tradeable
SpreadSpread -1.5
40¢ / 42¢
2¢
$31.1k
tradeable
SpreadSpread -2.5
31¢ / 32¢
1¢
$15.5k
tradeable
SpreadSpread -1.5
32¢ / 33¢
1¢
$11.2k
tradeable
SpreadSpread -2.5
23¢ / 26¢
3¢
$1.2k
tradeable
2¢
$17.1k
tradeable
SpreadSpread -1.5
50¢ / 51¢
1¢
$32.8k
tradeable
SpreadSpread -1.5
25¢ / 26¢
1¢
$9.8k
tradeable
SpreadSpread -2.5
16¢ / 18¢
2¢
$1.8k
tradeable
SpreadSpread -2.5
39¢ / 41¢
2¢
$16.6k
tradeable
1¢
$17.3k
tradeable
TotalsO/U 9.5
37¢ / 38¢
1¢
$15.3k
tradeable
SpreadSpread -1.5
39¢ / 40¢
1¢
$23.0k
tradeable
SpreadSpread -2.5
27¢ / 29¢
2¢
$12.9k
tradeable
SpreadSpread -1.5
31¢ / 32¢
1¢
$12.0k
tradeable
SpreadSpread -2.5
22¢ / 24¢
2¢
$2.3k
tradeable
2¢
$11.7k
tradeable
SpreadSpread -1.5
41¢ / 42¢
1¢
$33.9k
tradeable
SpreadSpread -2.5
30¢ / 32¢
2¢
$16.1k
tradeable
SpreadSpread -1.5
29¢ / 31¢
2¢
$11.2k
tradeable
SpreadSpread -2.5
21¢ / 23¢
2¢
$2.3k
tradeable
TotalsO/U 4.5
75¢ / 89¢
14¢
$4
thin
TotalsO/U 5.5
55¢ / 85¢
30¢
$13
thin
TotalsO/U 8.5
29¢ / 64¢
35¢
$415
thin
TotalsO/U 9.5
15¢ / 19¢
4¢
$11
thin
SpreadSpread -1.5
37¢ / 54¢
17¢
$11
thin
SpreadSpread -2.5
4¢ / 33¢
29¢
$5
thin
SpreadSpread -1.5
9¢ / 43¢
34¢
$11
thin
SpreadSpread -4.5
4¢ / 37¢
33¢
$10
thin
SpreadSpread -3.5
10¢ / 45¢
35¢
$16
thin
SpreadSpread -2.5
19¢ / 51¢
32¢
$227
thin
SpreadSpread -3.5
1¢ / 30¢
29¢
$8
thin
TotalsO/U 10.5
41¢ / 44¢
3¢
$3.1k
tradeable
TotalsO/U 11.5
3¢ / 29¢
26¢
$5
thin
TotalsO/U 7.5
3¢ / 97¢
94¢
$538
thin
TotalsO/U 8.5
3¢ / 97¢
94¢
$5.0k
thin
SpreadSpread -1.5
28¢ / 31¢
3¢
$2.2k
tradeable
SpreadSpread -3.5
1¢ / 89¢
88¢
$1.8k
thin
SpreadSpread -2.5
1¢ / 88¢
87¢
$59
thin
SpreadSpread -2.5
2¢ / 93¢
91¢
$2.0k
thin
SpreadSpread -4.5
2¢ / 51¢
49¢
$80
thin
SpreadSpread -3.5
1¢ / 49¢
48¢
$77
thin
SpreadSpread -1.5
4¢ / 46¢
42¢
$7
thin
TotalsO/U 9.5
50¢ / 68¢
18¢
$275
thin
TotalsO/U 10.5
3¢ / 52¢
49¢
$326
thin
TotalsO/U 5.5
47¢ / 87¢
40¢
$18
thin
TotalsO/U 11.5
5¢ / 54¢
49¢
$86
thin
SpreadSpread -1.5
4¢ / 40¢
36¢
$527
thin
SpreadSpread -3.5
— / 99¢
—
$9.9k
thin
SpreadSpread -2.5
15¢ / 64¢
49¢
$39
thin
SpreadSpread -2.5
4¢ / 50¢
46¢
$1
thin
SpreadSpread -4.5
— / 61¢
—
$4
thin
SpreadSpread -3.5
4¢ / 46¢
42¢
$4
thin
SpreadSpread -1.5
11¢ / 52¢
41¢
$173
thin
TotalsO/U 6.5
48¢ / 75¢
27¢
$4
thin
TotalsO/U 9.5
8¢ / 58¢
50¢
$75
thin
TotalsO/U 10.5
4¢ / 55¢
51¢
$34
thin
TotalsO/U 11.5
1¢ / 56¢
55¢
$54
thin
SpreadSpread -1.5
20¢ / 54¢
34¢
$86
thin
SpreadSpread -3.5
7¢ / 38¢
31¢
$13
thin
SpreadSpread -2.5
9¢ / 24¢
15¢
$1
thin
SpreadSpread -2.5
1¢ / 50¢
49¢
$8
thin
SpreadSpread -3.5
9¢ / 40¢
31¢
$10
thin
SpreadSpread -4.5
5¢ / 46¢
41¢
$4
thin
SpreadSpread -1.5
11¢ / 43¢
32¢
$124
thin
TotalsO/U 7.5
53¢ / 97¢
44¢
$4.8k
thin
TotalsO/U 10.5
2¢ / 65¢
63¢
$16
thin
TotalsO/U 9.5
3¢ / 54¢
51¢
$86
thin
TotalsO/U 11.5
2¢ / 97¢
95¢
$5.0k
thin
SpreadSpread -1.5
3¢ / 38¢
35¢
$1.8k
thin
SpreadSpread -4.5
4¢ / 88¢
84¢
$146
thin
SpreadSpread -3.5
1¢ / 65¢
64¢
$33
thin
SpreadSpread -2.5
5¢ / 28¢
23¢
$16
thin
SpreadSpread -1.5
3¢ / 46¢
43¢
$138
thin
SpreadSpread -2.5
1¢ / 47¢
46¢
$12
thin
SpreadSpread -3.5
18¢ / 47¢
29¢
$14
thin
50¢ / 92¢
42¢
$3
thin
TotalsO/U 5.5
25¢ / 84¢
59¢
$91
thin
TotalsO/U 8.5
23¢ / 88¢
65¢
$44
thin
TotalsO/U 6.5
10¢ / 82¢
72¢
$28
thin
SpreadSpread -1.5
3¢ / 97¢
94¢
$4.9k
thin
SpreadSpread -1.5
3¢ / 36¢
33¢
$13
thin
SpreadSpread -3.5
7¢ / 97¢
90¢
$5.0k
thin
SpreadSpread -2.5
1¢ / 97¢
96¢
$5.0k
thin
SpreadSpread -2.5
1¢ / 93¢
92¢
$4.8k
thin
SpreadSpread -3.5
3¢ / 89¢
86¢
$1.8k
thin
SpreadSpread -4.5
5¢ / 91¢
86¢
$70
thin
thin
TotalsO/U 9.5
29¢ / 51¢
22¢
$3
thin
TotalsO/U 8.5
9¢ / 51¢
42¢
$3
thin
TotalsO/U 4.5
12¢ / 99¢
87¢
$64
thin
TotalsO/U 10.5
10¢ / 51¢
41¢
$3
thin
SpreadSpread -1.5
2¢ / 38¢
36¢
$13
thin
SpreadSpread -1.5
42¢ / 45¢
3¢
$4.1k
tradeable
SpreadSpread -2.5
10¢ / 20¢
10¢
$1
thin
SpreadSpread -2.5
1¢ / 93¢
92¢
$2.1k
thin
SpreadSpread -3.5
1¢ / 55¢
54¢
$3
thin
SpreadSpread -4.5
1¢ / 55¢
54¢
$3
thin
SpreadSpread -3.5
2¢ / 44¢
42¢
$2
thin
Back the favorite — the one rumoured edge
Buy every favorite priced ≥ 70c, net of ~2c cost, significance clustered by fixture. In MLB moneylines it comes to too few high-priced favorites to test honestly — across all market types, −3.42c (t = -0.67). Null after cost — no free structural edge here either.
market type
bets
fixtures
net edge
t (clustered)
Moneyline
—
—
—
—
Totals
675
195
−3.15c
-0.55
Both teams to score
—
—
—
—
Spread
—
—
—
—
All types
678
195
−3.42c
-0.67
“—” means fewer than 8 favorites of that type — too thin to test. A real edge would need net > 0 andt > ~2.5 in a type that isn't just near-certain totals, and would have to survive out-of-sample.