MLB All-Star Game

Platform comparison

Market context

The 2026 MLB All-Star Game pits the American League against the National League in Philadelphia on 14 July, with the National League favoured to win at home. Traditional moneyline books list the NL at -142, implying roughly a 59% chance of victory, while Polymarket’s corresponding market shows the American League at +127 odds, translating to a 44% implied probability for the AL [1][3]. This divergence highlights how platforms frame risk differently: Kalshi uses decimal prices to express implied probability directly (59% for NL), whereas Polymarket displays decimal odds that require conversion, creating a noticeable gap in perceived value for the same outcome [3].

Historically, the home league has won the All-Star Game in 12 of the last 18 editions, with Philadelphia’s crowd expected to bolster the NL’s recent form. Prediction markets have consistently favoured the NL in this fixture, with Kalshi assigning 59% and independent analysts estimating closer to 63%, reflecting the home-advantage premium [3]. The current 70% YES probability on the American League in your target market appears to contradict this trend, suggesting either a mispricing or a unique platform-specific sentiment that traders should scrutinise against traditional odds.

Key catalysts include the final roster announcements and any late injuries to star players, which could shift momentum before the 8:00PM ET start. Traders should monitor coverage from Covers.com for real-time odds adjustments and roster updates, as these often trigger rapid probability shifts across platforms [1]. Fee structures also vary significantly: Kalshi charges a flat fee with full KYC, while Polymarket operates with lower fees but limited identity verification, affecting liquidity depth and price efficiency on this specific market [3].

Sources: 1 · 2 · 3

Methodology

We read MLB All-Star Game from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.