In order to improve their form, soccer teams who are having difficulties in the League often change their squad. However, whether this works or not and whether this information can be used in betting is yet to be discovered. In order to check this, data should be examined and see if relationship between the number of players used and relegation exists in soccer. 
Derby County is the only team that has ever scored the lowest, 11 points, in the 38 game Premier League in 2007/08. In this season they used 36 different players. In 2013/14, Fulham were relegated using even more players.
In general, the quality of those teams which are not among the strongest ones in a League is weaker. Namely, these teams have to call on all of their playing resources for numerous of reasons and these are selected from squad players whose are weaker.
Simon Gleave’s concept recognizes the split in the Premier League between habitual title contenders and the rest and this concept is known to be of ‘a superior seven’ and the remaining batch of thirteen regularly changing teams. Thus, it is important to look at the ‘remaining batch of thirteen regularly changing teams’ in order to see whether there is a correlation between results and squad usage.
What do numbers say?
If we use the statistics since 1999 and take into consideration the fifteen best performances from the pool of teams outside the superior seven, the findings suggest that all but one used 29 or less players over the season, with the average of just 24.5 players. This means that they used an average of six fewer players than the teams which finished at the bottom in the course of the same timeframe (30.4).
The graph below shows the relationship between fewer points and greater numbers of players since 1999. All of the teams from the Premier League, outside of the superior seven, have this correlation in common.
Relation of the performance to the number of players over a Season:
What we can see from the graph is that the fewer the number of core players are engaged in the field, the greater number of average points scored per game.
Why consistent teams matter?
The effectiveness of one team increases over a period if as little as possible changes appear on the field. This is true mainly because the players get accustomed with one another in terms of playing style.
The important thing to know here is the fact that, by knowing one another, one player can easily guess, by intuition, what the next move of the other may be. This is especially important for best striking partnerships. On the other hand, in defense terms, one team would only improve through practice and familiarity.
Why do weaker teams use bigger squads?
Continuously weak results call for change. And this is why a manager’s first reaction to constantly bad performance is to make the change. The easiest way to do this is to drop under-performing players and replace them with another player from within the squad. In certain cases, the reason for making changes is the change of the manager midseason in the first place. Considering himself a ‘fresh air’, his first reaction is changing the playing staff
There are some other examples, however. Crystal Palace, in the 20th, was appointed a manager, Tony Pulis, in 2014. After outperforming the usual achievements of every relegation threatened team since 1999 that used 31 players, they finished 11th.
Taking everything into account, according to statistics, using fewer players actually help the team. There is strong linear correlation between match outcomes and player churn within the season and the more the numbers of players rise, the more the points per game fall.
Why does this concern soccer bettors?
The nominal value of a player is still the most important for the overall results of one team. Thus, this should be the most significant fact that bettors should take into account when evaluating the abilities of one team.
If a team continuously changes personnel, this only implies that it is struggling and will continue to struggle more as the season progresses. This is usually a sign of a lack of talent depth.
To take everything into account, bettors should always be aware that correlation between stability of one team selection and increased league points for teams outside of the elite. However, team stability is only one factor which affects on the overall performance of a club throughout a season.