What Are The Chances?

I saw someone talking the other day about their idea of waiting until half-time in a match and then laying the current scoreline, "... as there is more value to be had".

I wondered what proof this person had available as they seemed very sure of themselves, but I asked myself if this was really true. Just because the odds are lower, does that necessarily make them value? Lower odds, it should be remembered, do not in themselves equate to value when laying. Thinking they do is a schoolboy error.

I suppose you can say that a loss won't hurt your bank as much as laying the 0-0 scoreline at the start of the match, but if we're seeking value, then we should really determine whether laying the current scoreline at half-time does represent value. The only way to do this is by looking at the data.

There is a well-known saying that "goals beget goals", and indeed there is some evidence to suggest that this is true - that if a goal or goals are scored early in a match, then there is a greater likelihood of further goals in the match; so it may be that if a goal is scored in the first-half, then bettors assume that there is more value available in laying the current scoreline at half-time as there "are bound" to be further goals in the second-half.

Last night, in the wee hours of the morning and after several Jack Daniels, I thought I'd take a look at the facts of these assumptions. Using data from the football-data website, I looked at the last five years worth of complete seasons in the English Premier League (so not including the current season). Using this data, I looked at four different scenarios:

Matches that were 0-0 at half-time
Matches that were 1-0 at half-time
Matches that were 0-1 at half-time
Matches that were 1-1 at half-time

Using these scenarios, I then set out to verify the number of times each available scoreline was recorded at full-time under those situations throughout the last five seasons.

The table of results can be seen in the downloadable spreadsheet (below), but the headline facts are that if a match is 0-0 at half-time, there is still a 27.32% chance (or fair odds of 3.66) of the match finishing 0-0.

Well I don't know about you, but I've rarely seen odds being offered at 3.66 or below at half-time, which would seem to indicate that there is no value here.

Okay, what about the other scenarios? What about 1-0, 0-1 and 1-1 at half-time?

1-0: 22.70% chance of remaining 1-0 (fair odds of 4.41)
0-1: 20.20% chance of remaining 0-1 (fair odds of 4.95)
1-1: 23.56% chance of remaining 1-1 (fair odds of 4.24)

Again, no value to be had here, as these scorelines are generally priced higher at half-time than 0-0. So it looks like our confident friend was barking up the wrong tree.

So does this mean there are no value scorelines that we can lay at half-time? Possibly - but this would be up to you to find out.

Take 0-1 full-time after 0-0 in the first-half. Fair odds for the game to finish at 0-1 are 7.66. There does seem to be a slight trend away from this scoreline (17, 20, 17, 13 and only 9 last year. So far there are seven 0-1s this season if 0-0 at half-time). I estimate for evenly-matched teams, the odds of 0-1 at half-time should be around 5.6 to 5.8, so there may just possibly be a little bit of value in laying 0-1 under certain games... but it doesn't look massively significant to me.

Anyway, all the tables are below. Have a look for yourselves and maybe you can spot some opportunities there.

Download results here.