One of the fundamental winning strategies employed by sports bettors over the past 20 or so years is known as "chasing steam". A steam move usually results when a syndicate or other heavy-betting, winning sports bettor decides to wager on a game. The larger, professional-friendly sportsbooks such as Pinnacle and CRIS/Bookmaker, who tend to take the big action from these players, will move their lines in response to this wager, after which the smaller sportsbooks will tend to copy the line move. Chasing steam is quickly betting the original line at other sportsbooks before they have had a chance to move their line as well.
Getting down on steam plays used to be a sure-fire way to win at sports betting without even having to handicap. It was easy money; simply put, the methodology was just too sound. If you manage to bet numbers that are as good as what the winningest players are betting, by definition, you have to win! And usually you'd win even more than whatever line value you got, if you followed the moves well, because you were always following long-term winners. As a result sportsbooks would constantly ban players for chasing steam moves, meaning the aspiring steam bettor needed a steady flow of trustworthy beards to stay in action.
Nowadays the market has changed and while you'd still usually prefer to be on the right side of these moves, understanding why the line moved is very important to betting steam profitably. Let's take a look at the three main reasons why a line can move at a major sportsbook and understand the implications to the steam bettor:
1. Key injury or roster news
In this situation an injury or lineup change is announced (via Twitter or some other source) which runs contrary to the previous market expectation. In most cases bettors will swiftly react to the news and hammer the corresponding side and total; in some situations bookmakers will take down their odds to protect themselves if they know the announcement is upcoming and post updated odds following the announcement. It is important that the lineup change is different from what was expected before; for example, if no one expected Tom Brady to play anyway, an announcement of him being out would not really affect the line.
For the steam bettor, and often even handicapper, who is following the news and getting down at the pre-news number these plays are always profitable as long as the size of the injury impact is substantial and the injury truly is a surprise. The only issue to watch out for is that some players may have had insider information and placed their bets early knowing they could get better value on their play betting before the likely announcement. In this type of situation, the line will usually move, then swing back to where it was before the announcement (possibly even from these players covering their position) as the injury was already reflected in the line, and those generating the move were not true sharps but just "news players" looking to get down fast on the information. This tends to happen quite often in financial markets too, including those where trading on insider information is supposed to be illegal, but that is a subject for another day.
My personal experience in handicapping is that the line tends to move roughly as much whatever the injury impact is, but perhaps not quite as much as one would expect, especially for the larger sports like NFL/NBA. Part of this is probably due to insider information, and part is simply due to the fact that for the really key players, there is almost always some kind of indication or news they may have been banged up in the previous game or practice.
In summary these are usually solid winning steam plays and if you can confirm the move is legitimately due to an unexpected injury or roster move, you should definitely bet with confidence. However, you will need to be lightning fast, or have really slow sportsbooks, and constantly be on top of news (and the Don Best screen doesn't count as it is usually slow) in order to take advanage of this type of informational wagering.
2. Increase in wagering limits
In many markets wagering limits will sharply increase around mid-morning the day of the game. For weeklong markets like football, there may be other increases as well such as on the Thursday before the game. Many smaller sportsbooks who do nothing other than copy lines from Pinnacle or CRIS will only put up a line once either of these books has reached max limits.
The overnight or opening limits on offer, typically a few thousand dollars, tend to be pretty low especially for the really large betting syndicates, who in addition to the major books like to take advantage of all kinds of smaller, local or "pay per head" sportsbooks who copy the major books in order to increase the volume of their wagers. As a result these syndicates will usually wait until the sportsbooks increase their limits to do any serious betting. This would seem to indicate that chasing steam right around the increase of limits in the morning would be a winning strategy, and usually that will be the case.
However in modern sports betting, the amount of money that can be wagered at smaller sportsbooks, who copy the major sportsbooks, in aggregate is often many times what can be wagered at major sportsbooks alone. This is because it is usually straightforward to get many accounts at this type of sportsbook, and contrary to the major sportsbooks, these books will not move their lines on an individual wager, so every account can get the "good" betting line.
This leads to the optimal strategy often being for the syndicate to look to make wagers against the side they like right before the potential increase in betting limits. They will then take advantage of more favorable prices at the copying/following smaller sportsbooks to establish their true position. Finally they will cover their position as quickly as possible at the major sportsbooks (if the limits at major books still represent a substantial portion of their overall wager).
The challenge to this strategy is that the timing of limit increases is often uncertain, yet it pays off to put in the fake play as close to the increase as possible, because if they go too early, other sharps might go ahead and bet the play back. What can often happen is that the sharp syndicate may miss out on the increase, but still decide that it is profitable to put a head fake on to slightly improve their number. So they'll bet the wrong side at the limit increase even if it costs them more to do so, then cover later.
For the steam bettor, who does not handicap the games and therefore does not know the real side of the play, chasing moves at the open of full limits is therefore challenging. It is easy to chase a "fake steam" move and be on the complete wrong side of the play, which will lead to taking way the worst of the number and of the overall wager in general. Furthermore, chasing any move that happens right before max limits is terrible and should always be avoided, so it is necessary to keep track of limit increases at the big sportsbooks, a major hassle.
There are two main factors that a steam bettor can use to determine the legitimacy of steam moves in this situation. Probably the most important is to consider the betting limits of the major sportsbook in question in comparison to the size of the rest of the market. There are many fairly obscure sports out there where Pinnacle has decent betting limits, some as high as $5/10k, yet it is very difficult to bet that much on all other sportsbooks combined. In these sports, chasing Pinnacle steam moves is usually a solid winner as there is not much value in fake moves in this type of market. A review of line moves in these types of Pinnacle-dominant markets usually shows a constant flow of line moves in one direction as sharps line up on one side of the play. In other sports, such as say college basketball, Pinnacle has very small limits, yet tons of books still copy them or at the very least are heavily influenced by their line. In this type of sport chasing steam can be very dangerous indeed.
A second factor is the tenor of the action coming in. For example, consider a basketball game that at 8:30 is -8.5, then when limits fully open at 9:30, moves to -9, -9.5 and then -10 in what appears to be separate plays made 10-15 minutes apart. This type of move is very unlikely to be fake and if you can get, for example, -9 right as the line moves from -9.5 to -10, you are almost always going to be on the right side of the move with a positive expectation wager. It is just too unlikely that when multiple sharp groups on are the same side of the game, that the other side can ever be right.
However, if the same game goes from -8.5 to -8, then back to -8.5 and -9, it is possible that someone is looking to make a move on the game. This type of two-way action often occurs when a group is trying to hold the line on a game to get down big. It could well be that taking +9 is the actual play, and that taking +8 may even be better than taking -8.5! On the other hand, the initial move from -8.5 to -8 may have been the setup move. Or, there may simply be two groups legitimately on two sides of the game, particularly if they can get numbers they like. There is simply no easy way to tell with a move like this and it is better to sit on the sidelines.
3. Late steam
The final type of common steam move occurs right before the game. There are a couple of reasons for moves at this point. One, in some sports, syndicates will place wagers at their various smaller outfits throughout the day (some do not have lines until very late as that is when squares tend to play), then will finally go ahead and bet at major books right before the game to get additional action.
A second reason for a late steam move is that there tends to be additional information that comes out to the public right before the game. For example, the pitcher's warmup in baseball, the conditions of the field or ice in football and hockey, and in many sports the officials are announced around this time as well.
The common thread with both is that there is little reason for the action coming in to be on anything other than legitimate news, or legitimate handicapping, that truly should influence the line of the game. So chasing late steam moves is usually going to be profitable. The only issue is that the line tends to be at its sharpest during this time of day. So as where, if someone can read the market well at the increase of limits, they may be able to get down on a game at -8 that is on the move to -9 and eventually goes to -10, it is very unlikely that one can ever profit by more than the size of the move when playing near game time. Furthermore, there tend to be few big moves as a lot of the information that comes out at game time was already known by insiders. Still, overall these late steam plays should be profitable.
Overall, chasing steam can still be profitable, but many line moves these days are occuring for reasons other than legitimate news or sharp action, and chasing these moves is the opposite of profitable. Furthermore, books are way quicker to adjust their lines than they were in the past, and are also much quicker at banning winners. It is a tough way to make money, but there are still people out there that do it, and for most people, it is probably still easier than actually handicapping games well enough to have an edge.