Impact of Relegation from Premier League to Championship

Last week I posted about the promotion of teams from the Championship to the Premier League and how playing at a higher level will impact the stats of those teams.  Now I will take a look at the teams relegated from the Premier League and how their stats are affected when playing at a lower level.

	Points	GF	GA	% Promoted
Premiership Results/Match	0.85	0.97	1.71
Championship Results/Match	1.56	1.46	1.17	27%
Change	0.70	0.49	-0.54

The newly relegated teams score 0.49 more and allow 0.54 fewer goals per match which is an improvement in net goal differential of 1.03 per match.  Teams that are promoted into the Premier League see their goal differential decrease by 1.15 per match so it appears that moving between these two leagues will have about a ±1.1 goal/match impact on goal differential.


Applying the rate changes from the above table to the results of the 2011 relegated teams will give us the following projections for their Championship performance in 2012:

Club	League	Season	Matches	Points	GF	GA
Birmingham	Premier	2010-11	38	39	37	58
	Championship	2011-12	46	80	67	45
Blackpool		2010-11	38	39	55	78
	Championship	2011-12	46	80	89	70
West Ham United	Premier	2010-11	38	33	43	70
	Championship	2011-12	46	72	75	60

The 80 points that I'm projecting for Birmingham and Blackpool will probably not be enough to earn a Top 2 finish and automatic promotion.  Over the past 19 seasons, the teams that finished in the top 2 in the Championship have averaged 90 points.  The teams that have finished second averaged 86 points.  Only 4 teams out of 38 have earned auto-promotion with 80 or fewer points.  I would expect that all three teams will vie for a playoff spot next season.  The average points earned by teams that were promoted through the playoffs is 76.


I noted above that 27% of teams relegated to the Championship are able to turn around and earn promotion the following season.  The rate at which teams promoted to the Premier get relegated the following season is 47%.  So why would relegated teams that are dropping into a lower-level league be less likely to earn promotion?  I think that there are two factors driving this:

1. There are only two automatic promotion spots in the Championship.  The third spot is contested by the four teams ranked 3rd through 6th.  So that's three additional matches that would have to be played (the last of which has to be a victory) to earn promotion.  These teams are pretty comparable so anything can happen and usually does.
2. The loss in income that results from relegation often forces teams to sell key players to help stay profitable at the lower level.  So as talent level diminishes, the chances of earning promotion also diminish.

My early picks for the two promotion spots in 2012 are Reading and Cardiff City.  I expect that the three relegated teams will be in the playoff mix along with Nottingham Forest.

Impact of Promotion from Championship to Premier League - Part II

Yesterday I posted about the changes in promoted teams' stats in their first season in the Premier League.  On average, newly promoted teams reduce goals scored by 0.55/game, increase goals allowed by 0.60/game and reduce their points earned by 0.81/game.  I now want to apply those rates against the Championship stats of the three promoted teams to estimate how they will fare next season.

First, Queens Park Rangers with 88 pts,  71 goals scored and 32 goals allowed.  They averaged 88/46 or 1.91 points/match.  If we reduce this rate by 0.81 then they would earn 1.11 points/match in the Premier League or 42 points over a 38-game season.  This would most likely guarantee survival as only two teams have been relegated with as many as 42 points (Middlesborough 1997 and West Ham 2003) since the league went to 20 teams in 1996.  Their goal scoring rate would decline from 1.54 to 1.00/game or 38 goals.  Goals allowed would increase from 0.70 to 1.30 goals/match or 49 goals for the season.  The table below summarizes each team's projected results:

 

Club	League	Season	Matches	Points	GF	GA
Queens Park Rangers	Championship	2010-11	46	88	71	32
	Premier	2011-12	38	42	38	49
Norwich City	Championship	2010-11	46	84	83	58
	Premier	2011-12	38	39	48	71
Swansea City	Championship	2010-11	46	80	69	43
	Premier	2011-12	38	35	36	58

So I would expect QPR to survive.  The odds for Norwich and Swansea are not as good.  40 points is generally considered the safety threshold, but teams have survived with as little as 34 points (West Brom 2005).  Norwich has a decent chance of avoiding relegation at 39 points but I can't see Swansea  also surviving at 35 points.  Only in 2001 did all three promoted teams avoid relegation.  So my prediction is that QPR will survive, Norwich has a 50/50 chance and Swansea will be relegated.

Impact of Promotion from Championship to Premier League

Swansea City won the League Championship playoff final on Monday earning their first-ever promotion to the Premier League.  The Swans will become the first Welsh team to play in the Premiership.  They join Queens Park Rangers and Norwich City as next season's newcomers.  Obviously these three will be facing a higher level of competition, but can we quantify how much tougher it is? 

I decided to compare the performance of teams in their promotion season to their prior season in the Championship to measure the difference in quality between both leagues.  Going back to the 1993-94 season, 53 teams have been promoted from the Championship (or First Division as it was previously named) to the Premier League.  The table below shows the average changes in points and goals after promotion:



	Points	GF	GA	% Relegated
Championship Results/Match	1.87	1.67	1.00
Premiership Results/Match	1.06	1.12	1.60	47%
Change	-0.81	-0.55	0.60

A little less than half of the promoted teams were relegated after one season.  These teams had an average goal differential of 0.67/match in the Championship but this dropped to -0.48/match in the Premiership.  Net change was 1.15 goals/match worse than the Championship season. 

So can we say that teams from the Premier league are 1.15 goals/game better than their Championship counterparts?  Maybe so but since we are comparing results from one season to the next we have to account for changes in players, changes in management and changes in spending.  Currently a promotion to the Premier League is estimated to provide about £90 million of additional income to the promoted teams.  How they choose to spend that money can have a big impact on their performance.  

However, the impact of those factors (players, managers, income) is hard to quantify.  So more work needs to be done in this area to refine this, but for now I'm using the 1.15 goals as a yardstick to differentiate the quality levels between the leagues.