What the Odds Say
Joo Sang Yoo enters this MMA bout on Sunday, September 20 as a clear favorite across every sportsbook carrying the matchup. The consensus moneyline sits around -278 for Yoo at most books, with FanDuel pushing that number to -294. Michael Aswell is listed as the underdog, with prices ranging from +200 at Betfair Sportsbook, Paddy Power, and Sky Bet up to +245 at Kalshi.
The 45-point gap in Aswell's underdog price is meaningful. Bettors looking to back Aswell should be shopping lines before placing a bet.
Implied Probabilities: Joo Sang Yoo vs. Michael Aswell
At -278, the market prices Joo Sang Yoo with an implied win probability of roughly 73.5%. Aswell at +215, a midpoint across most books, carries an implied probability of around 31.7%. The overlap reflects the vig built into the lines, which is standard across MMA markets.
At FanDuel's -294, Yoo's implied probability climbs to about 74.6%. Kalshi's -256 implies roughly 71.9%. Bettors considering Yoo will find the best value at Kalshi, followed by BetOnline.ag and Caesars Sportsbook at -263.
For bettors who want to strip out the juice, the Odds Converter makes it easy to flip between American, decimal, and fractional formats and get a clearer read on true implied probability.
Line Shopping Highlights
Here is a quick snapshot of where the notable differences sit:
On the Favorite (Joo Sang Yoo)
- Best price: -256 at Kalshi
- Worst price: -294 at FanDuel
- Most common line: -278 across 1xBet, Betfair, DraftKings, Paddy Power, Sky Bet, and Unibet
On the Underdog (Michael Aswell)
- Best price: +245 at Kalshi
- Second best: +225 at DraftKings, +220 at BetOnline.ag and FanDuel
- Worst price: +200 at Betfair, Paddy Power, and Sky Bet
Kalshi is the clear standout for underdog bettors, offering a full 25 points better than several major books. That kind of gap can shift expected value in a meaningful way.
The draw is listed at +3200 on 1xBet, implying under 3%. Draws are rare in MMA but not impossible.
The Totals Market
The over/under is set at 2.5 rounds across every book offering the total. The Over is priced at -200 to -208 across 1xBet, BetOnline.ag, and DraftKings, implying a 66.7% chance the fight goes beyond 2.5 rounds. The market expects this one to go at least into the third.
The Under shows more variation: BetOnline.ag at +169, DraftKings at +160, and Novig at +153. If you think this fight ends early, BetOnline.ag offers the best return. The 16-point swing between BetOnline.ag and Novig on the Under is another reminder that totals markets reward line shopping too.
What to Watch Before Fight Night
Line movement on Aswell. The 45-point spread across books suggests the market has not fully settled on the underdog price. If Aswell's number starts dropping simultaneously across multiple books, that could signal sharp money on Yoo. Track this using Steam Moves on Line Whale.
Late scratches and injury news. MMA markets move fast when fighter health information surfaces close to fight time. Books typically react quickly, so monitor news on both fighters in the days leading up to Sunday.
Total relative to the moneyline. A heavy favorite at -278 does not automatically mean a short fight. The Over priced at -200 signals a market lean toward a longer bout, which is worth factoring into any multi-leg plays. The Parlay Calculator is useful for working out combined implied probabilities before committing.
Book availability. Not every sportsbook listed here is available in every US state. Confirm a book is accessible in your jurisdiction before targeting a specific line.
Bottom Line
Joo Sang Yoo is the consensus favorite at roughly 73.5% implied probability, with the market broadly aligned on his edge. The opportunity for bettors is in the details: a 45-point swing on Aswell's underdog price and meaningful variation in the totals market mean where you bet matters as much as what you bet. Compare your options before locking anything in.