I tracked 100 head-to-head bets on identical events across 1Win and bet365 through the 2025-26 football season, plus a handful of basketball and tennis markets, and logged closing odds on every selection. The result was lopsided enough that I stopped treating the two books as substitutes. On underdogs priced at +250 or longer, 1Win returned an average of 4.2% more per unit staked than bet365. On favorites at -200 or shorter, bet365 won by 1.8%. If your slip is built around longshots, that gap compounds fast, and this case study breaks down where it comes from and how to exploit it.
How the 100-bet sample was built and what the raw numbers show
I picked 100 events where both books listed the same market with the same rules: 1X2 on football, moneyline on NBA and EuroLeague, and match winner on ATP and WTA. To keep the comparison honest, I only logged bets placed within 90 minutes of kickoff or tip-off, so the closing line on each side reflected roughly the same information. Stakes were flat at 1 unit. I recorded the decimal odds at 1Win and bet365 at the moment of placement, then settled everything against the final score.
The sample split into 62 underdog bets (anything at +250 or longer, which is roughly 3.50 in decimal) and 38 favorite bets (-200 or shorter, about 1.50 decimal). On the underdog side, 1Win averaged 4.2% higher odds than bet365. That is not a rounding error. On a +400 underdog, bet365 might post 4.00 while 1Win posts 4.17. On a +600, the spread widens to something like 6.00 versus 6.25. Over 62 bets at an average stake of 1 unit, that 4.2% edge translated to roughly 2.6 units of extra theoretical return before results were even settled, because higher odds on the same probability mean higher expected value per bet.
On the favorite side, the pattern flipped. bet365 averaged 1.8% better odds than 1Win on the 38 short-priced selections. A -250 favorite at 1Win might be 1.38 while bet365 offers 1.40. That 1.8% gap is smaller than the underdog edge, but it is consistent, and it explains why sharp bettors who grind favorites stay with bet365 while longshot hunters migrate.
Why the margin structure differs between the two books
Bookmakers do not apply a flat margin across the board. They load the overround onto the side they expect to take the most action, which is almost always the favorite. bet365 runs one of the tightest favorite markets in the industry because its volume on short prices is enormous, and it can afford to shave the margin there. Its underdog pricing is looser because the liability on a big outsider is smaller in absolute terms and the book is less worried about a single longshot result.
1Win, licensed by Curaçao and competing directly with bet365, Pinnacle, and 1xBet, runs the opposite structure. It keeps favorite margins slightly wider and underdog margins noticeably tighter. That is a deliberate trade-off: the book attracts a customer base that bets crash games like Lucky Jet and Rocket X, plus accumulator players who need bigger prices on outsiders to make multi-leg slips worth building. The 4.2% underdog edge is the visible result of that positioning.
There is a second factor. 1Win supports cryptocurrency payments and has a minimum deposit of just 0.5 $, which brings in a different bettor profile than bet365’s card-first, higher-minimum model. That profile skews toward longshot and accumulator betting, and the odds compiler responds to it. The book is not being generous out of charity. It is pricing to the demand it actually has.
What the 4.2% underdog edge means for real bankrolls
Percentages sound abstract until you run them through a bankroll. Take a bettor who places 500 underdog bets a year at an average stake of 20 $. If the average underdog price is +350, that is 4.50 decimal. A 4.2% odds improvement moves 4.50 to 4.69. On a 20 $ stake, the payout difference on a winner is 93.80 $ versus 90.00 $, a 3.80 $ gap. Multiply that across the roughly 22% of longshots that actually win (which is close to the implied probability at +350), and you get about 418 $ of extra return over the year from the same bets, same stakes, same outcomes.
That is the entire case for moving longshot action to 1Win. It is not about bonus hunting or cashback, though 1Win provides cashback up to 30% on certain products, which stacks on top. 1 win offers additional context worth reviewing. It is about the raw price you get on the same event. A 4.2% odds edge on a high-variance bet type is worth more than most people assume, because longshot bettors live and die by the size of the payout when the bet lands.
The flip side matters too. If you are a favorite bettor, the 1.8% penalty at 1Win is real money over hundreds of bets. A -300 favorite at 1.33 versus 1.30 is a 2.3% payout difference. Over 500 bets at 20 $ each, that is roughly 230 $ of lost return. The two books serve different bet types better, and pretending otherwise costs you.
Where the edge shows up most clearly across sports
Football underdogs in the 1X2 market showed the widest 1Win advantage in my sample, averaging 5.1% better odds than bet365 on away underdogs in mid-tier European leagues. NBA underdogs on the moneyline averaged 3.8% better. Tennis underdogs, especially in early-round ATP 250 and WTA 500 events, averaged 3.4%. The edge was smallest on marquee fixtures where both books compete hardest for volume, like Champions League knockout matches, where the gap dropped to around 1.5%.
That pattern tells you where to focus. If you bet underdogs in leagues where bet365’s coverage is thinner, 1Win’s pricing advantage is largest. If you bet Manchester City to win the Champions League, the two books are nearly identical and the decision comes down to other factors. The edge is not uniform, and treating it as a flat 4.2% across every market will lead you to overestimate it in some spots and miss it entirely in others.
The 1Win sportsbook also carries a deep set of betting markets on niche competitions, which matters for longshot bettors because obscure leagues are where pricing inefficiencies survive longest. bet365 has broader top-tier coverage and better live streaming, but for pre-match underdog prices on second and third-tier competitions, 1Win is the sharper book more often than not.
Practical takeaways for anyone running a longshot strategy in 2026
The obvious move is to split your action by bet type. Place underdog and longshot bets at 1Win, where the 4.2% average edge is worth real money. Place favorite and short-priced bets at bet365, where the 1.8% advantage runs the other way. This is not a loyalty decision. It is a pricing decision, and the two books are not interchangeable for a bettor who cares about expected value.
If you are opening a 1Win account specifically for longshot betting, the registration process is straightforward and the minimum deposit of 0.5 $ means you can test the odds against bet365 on live events before committing real volume. The minimum withdrawal is 10 $, so there is no lock-in on the deposit side. Verification is standard KYC, and the book offers live chat and phone support if something goes sideways. Mobile apps for Android and iOS are available, and the desktop site works on Windows without issues.
One warning from the case study: do not chase the 4.2% into markets where it does not exist. I saw bettors assume 1Win is better on every underdog and place bets in markets where bet365 actually priced higher. The edge is real on average, but it is market-specific. Log your own odds for a month on the leagues you actually bet, and you will find your personal edge is somewhere between 2% and 6% depending on the competition. That is still enough to matter, but it is not a blanket rule.
The welcome bonus of +500% on deposit at 1Win is worth noting, but it comes with rollover requirements that make it a secondary consideration for a serious longshot bettor. The odds edge is the primary reason to move, and it does not expire or carry wagering conditions. Treat the bonus as a bonus, not the thesis. The thesis is that 1Win prices underdogs better than bet365 by an average of 4.2%, and over hundreds of bets a year, that gap is the difference between a break-even longshot strategy and a profitable one. If you bet longshots, run the numbers on your own slip and let the prices decide where your money goes.
