Impact of the transfer windows on sports betting

As the excitement builds at the start of a new season, every punter across the land is busy evaluating their wagers. After all bets are in, it’s time to sit back and relax, right? Well, not exactly. That’s because the transfer window/trade deadline in sports like Football and Basketball can quickly turn things upside down. All of a sudden, pretenders become contenders, top dogs become underdogs, and wagers such as prop bets and accumulators are transformed.

What is a transfer window?

A transfer window is the period during the year in which Football teams can add players to their squad who were previously under contract with another club. Such a transfer is completed by registering the player into the new club through FIFA.

“Transfer windows” are the unofficial term colloquially used by the media for the concept of “registration period”, whereas in other sports such as the NBA and NFL, a transfer window is known as a trade deadline.

From an online sports betting perspective, deals made during this period can bring about a certain amount of uncertainty to the landscape. All of a sudden, a transfer window can shift a team or player’s odds for better or worse. That includes different milestones and misfortunes such as winning a championship, the race for a Golden Boot, clinching playoff qualification or even getting relegated.

Potential pitfalls and benefits of a transfer window on outright bets

In the NFL, for instance, most seasons kick off around early August. The issue is that most transfer windows shut in late August. For example, the 2024/2025 Premier League season starts on August 17, while the transfer window shuts on August 30.

This could impact outright bets in various forms. For example, imagine a typically mid-table team losing their star striker in the window, making them a contender for relegation. But in sports betting, one punter’s pitfall could end up as another’s gain. That’s because an outright wager such as Ipswich Town to avoid relegation could be boosted if they make some useful additions during the window.

When making outright and seasonal, sports bettors need to factor in the transfer window, especially if there are transfer rumours cicrcling around about players on their wagered teams. On the flip side, some punters could even extract value bets from transfer speculation that would potentially strengthen or weaken a team as well.

NBA trade deadline moves that changed betting odds

The New York Knicks have long since been eliminated from the 2024 NBA Playoffs but a couple of trades did cause an uptick to their season. But during the season, after losing Forward Julius Randle to a season-ending injury, they sent R.J. Barrett and Immanuel Quickley to the Toronto Raptors in exchange for O.G. Anunoby and Precious Achiuwa.

And after many sportsbooks moved the Knicks’ title odds from 22.0 (+2,100 ) to 17.0 (+1,700), the New York outfit responded with the best record in the league post-Christmas.

NHL Hockey trades and betting odds

As the world gears up for the 2024 Stanley Cup, one of its participants can thank the trade deadline for helping them get this far. In the space of a week, the Panthers went from around 9.5 (+850) to 6.5 (+550) with some sportsbooks after trading for veteran forwards Vladimir Tarasenko and Kyle Okposo back in March.

It turns out that the sportsbook were spot on because, ever since the trades, Florida has had the best record in the league. Now fast forward to June, they’ll be facing the Edmonton Oilers for all the marbles.

Predictably, on the flipside of great NHL trades are bad ones. And in the North America’s premier division, bad trades get their own their bizarre form of recognition.

That’s because the trades that end up ruining a team’s Stanley Cup chances are awarded the “Conned” Smythe trophy, the unofficial cousin to the legitimate Conn Smythe MVP trophy, named after the legendary Canadian soldier Constantine “Conn” Smythe.

An NFL trade deadline betting scenario

Just like the NBA, the NFL is also subject to a trade deadline. One great example of a trade deadline move that had a positive impact was the Los Angeles Rams trading for Von Miller from the Denver Broncos and Odell Beckham Jr from the Cleveland Browns in the 2021/2022 season.

Even though most sportsbooks didn’t budge on their Rams Super Bowl odds, with many standing pat at around 8.5 (+750), Miller and Beckham Jr’s contributions were both needed by the Rams as they inched past the Cincinnati Bengals to win the championship.

Typically, a move like this would cause movements in the odds but, just like other NFL franchises, sportsbooks were concerned by Miller and Beckham’s Jr’s injury-plagued history.

Zinedine Zidane to Blackburn Rovers and Kaka to Manchester City. These are just two stories that worked the rumour mill back in the day. While the former inspired a BBC podcast about the greatest “what ifs” in Football, the latter inspired one City fan to get a tattoo announcing them as 2011 Champions League winners before the tournament even started.

In today’s social media age, rumours, lies and a mixture of both can cause betting odds to shift. Sometimes, fan interaction can even create new betting opportunities.

Remember back in 2017 when former Real Madrid and Spain defender Fernando Hierro became an unlikely tip for the Leeds United managerial position, largely due to social media. That’s because a Twitter user messaged a famous sportsbook asking for Hierro to be added to the Leeds United manager betting market. The sportsbook agreed, and listed Hierro’s odds at 34.0 (+3,300).

After seeing Hierro’s name amongst the contenders, many people began wagering on his appointment, and social media speculation went into overdrive. This process eventually drove down his odds to 3.0 (+200) - leading some publications to label Hierro a favourite for the job.

Ultimately, Leeds did get a Spanish manager, only it was the relatively unheard of Thomas Christiansen Tarín who was actually born in Denmark. Go figure.

When trades don’t live up to the hype

When the circumstances change, should punters change their minds? Well, yes and no.

Circumstances, like trade and transfer window deals should make sports bettors reassess their current bets and weigh up new ones. Maybe a transfer window signing might signal the right moment to use a Cash Out option? Alternatively, that same trade could make it correct to double down on an initial wager.

For example, when Lionel Messi signed for Paris Saint-Germain (PSG), their Champions League odds went from 13.0 (+1,200) to 4.0 (+300) with some sportsbooks.

In the end, the move didn’t help PSG capture the prize they desire the most. But for some punters it was worth punting on the anticipated positive expected value (EV) bets on offer while PSG’s UCL odds were tumbling.

Although these expected value (EV) bets didn’t end up paying off, the strategy behind them was sound.

Trade deadline deals typically cause a level of uncertainty amongst bettors and sportsbooks and make them re-evaluate the implied probability of certain outcomes.

Let’s imagine that the Dallas Cowboys acquire Tom Brady at the next trade deadline. As Brady’s’s been retired for a while now, most sportsbook don’t see the move improving the Cowboys Super Bowl odds.

But for some punters, they notice their own calculations for a Cowboys Super Bowl win differ significantly than the implied probability of the odds. In this scenario, these bettors could see where to find a positive expected value (EV) and therefore the best chance to win.