The Dallas Cowboys have, in striking detail, shown us the incredible impact a midseason coaching change can have on a team. Under Wade Phillips the Cowboys were lousy all year, and played their worst game of the season just prior to his demise. Offensive coordinator Jason Garrett was handed the keys on Monday, and by Sunday he had his squad looking like a real NFL team for the first time all season.

It’s not just that they finally won a game, or that they kept turnovers and boneheaded mistakes to a minimum. It’s that they went on the road to play perhaps the best team in the NFC up to this point, and they dismantled them. It was the game that the team was supposed to be able to play all year. Suddenly Garrett looks like a genius.

The short term success in Dallas has fueled optimism, and has fans of other teams and in other sports hoping for changes as well. The New York Islanders became the first NHL team of the year to make a change, and the NBA - a notoriously fickle coaching league - will likely have their first change made soon. All of this change presents a challenge for NFL handicappers - they have to try to assess what impact the changes will have on teams. Here are four general things to keep in mind when you are trying to figure out the impact.

Short-term boost - We typically see a short-term burst of success after a change is made. There are all sorts of reasons for this.

If the team was tense because of the coaching situation then a change could provide release. If the coach was clashing with key players then those players will feel better and play better. If the players are fearing the new regime and the changes that could come with it then they could be playing for their lives - or at least their careers. Whatever the reason, It’s typical to see a boost for a short while after the change.

Back to earth - Most of the reasons why a team plays well after a change are due to one factor - adrenaline. The change has, for some reason, created a boost in adrenaline among the players, and the excitement or fear of the situation forces them to perform at a higher level than they have been performing.

In most situations, though, the boost from adrenaline is not sustainable. A change is often needed to be made because players are getting lazy, so teams can often play better if that laziness is is addressed and eliminated.

Still, the boost of adrenaline goes beyond just that laziness. Inevitably the effort after a change will diminish after a few games. This is where the betting public tends to make mistakes in these situations. They will assume that the short term success will continue - that Dallas is turned around because of what they showed in one game, for example - and they will bet the team accordingly.

The public believes in miracles, but the slow, gradual change is more of the reality in sports. That means that there is often a chance to grab real value in the games following after the immediate euphoria.

What are the problems? - To really assess the lasting impact of a change for the rest of the season you have to look at what the state of the team is.

A couple of years ago the Chicago Blackhawks made a dramatic coaching change early in the season because everything was going badly. The change led to very positive results, but that couldn’t be viewed as a surprise - the core of talent that the team had was very strong, so the new coach had a lot to work with.

More often, though, a team that makes a change has fundamental issues that have caused their problems in the first place. The new coach can very likely get them playing better and showing a better attitude, but they can’t create players out of thin air. As the saying goes, coaches are only as good as the players they are coaching. Looking at the rosters and the situation, then, is crucial.

The public will often overestimate the impact of coaching changes - especially if the new coach has a strong reputation - because they won’t consider the limitations of the players as much as they should.

Who is the coach? - Some coaches are able to step in right away and command the respect that will allow him to make the changes that he needs to make. Other coaches are being put in a tough spot.

Spending some time looking at who the coach is and whether they have a good chance at making lasting changes is time well spent. In hockey, for example, promoting a team’s AHL coach to the NHL can often work well - in part because that coach already has a relationship with the younger players on the team. On the other hand, moving an assistant coach on the NHL team over to the head coaching role almost never works because that’s not a transition that is typically made in the league, so when it does happen it is viewed as a stop-gap, and not as a lasting solution the team has faith in.