Another Betting School article. This time one I originally wrote in November 2010. This one looks at full time outcomes based on half time results.
When the half time whistle goes and you get the urge to make a bet is there anything the first half can tell you? Of course you will have seen how the match has panned out and make judgements on what you think will happen but can stats help? The aim of this article is to look at a few of the in-play markets on Betfair and see if we can get some valuable pointers to the outcome of the game based on the half time result.
The data I am looking at is from the top division in England, Spain and Italy for the seasons from 2005-2006 to 2009-2010. The statistics and pre-match odds for the 5700 matches come from the treasure trove that is www.football-data.co.uk .
The in-play data was downloaded from the Betfair data site and is for the entire 2009-2010 season. The Betfair data files contain so much information that all I have is the in-play data so the pre-match prices come from football-data. I have taken the half time data as prices that occur 50 minutes after match kick off.
Strong Favourites
The idea for this article came when watching Real Madrid away at Levante this season which was scoreless at half time. Looking at the data for the game I can see at kick off Madrid were matched at 1.24 on Betfair and this increased to 1.39 at half time. I was convinced they would win and as the odds drifted, I decided they were great value and at half time and made my bet.
Let’s look at the results of some of these strong favourites. In the last 5 seasons in the 3 leagues I am using there were only 13 occasions when the away team was priced 1.3 or below. Interestingly on 6 of those occasions they were drawing at half time and went on to win. An example is Real Madrid on 13/02/2010 at Xerez when they were also drawing 0-0 at half time. On this occasion they started the game at 1.27 and could have been backed at 1.47 at half time before going on to win 3-0.
That’s not enough data so let’s look at home strong favourites, which I classify as teams priced at 1.3 or less using BbMxH (Betbrain maximum home win odds). All in all there have been 344 of these matches and the home team won 293 (85%) of these games. If we look at games that were draws at half time we are left with 114 matches and the home team won 85 of them (74%). To break even backing those teams we would need odds of 1.41 taking into account betfair commission of 5%. I have chosen 4 of those games to look at the Betfair data and get an idea of the sort of odds available.
|
Div |
Date |
Home |
Away |
First Match Odds in play |
Match odds at HT |
|
Eng Prem |
26/12/2009 |
Liverpool |
Wolves |
1.3 |
1.61 |
|
Ita Seria A |
09/01/2010 |
Inter |
Siena |
1.23 |
1.56 |
|
Eng Prem |
31/10/2009 |
Man United |
Blackburn |
1.22 |
1.46 |
|
Spa Primera |
26/09/2009 |
Real Madrid |
Tenerife |
1.11 |
1.3 |
In 3 out of 4 of these games the price required is reached and the game that didn’t had the home team ridiculously short (only 18 of the 114 matches had home odds lower than 1.2). This looks like a strategy with some promise but are there any angles that strengthen the chances of the game ending in a home win? Let’s check by leagues
|
Div |
HT Draws |
Won |
Drew |
Lost |
Win % |
|
Eng Prem |
59 |
42 |
16 |
1 |
71% |
|
Ita Seria A |
27 |
18 |
8 |
1 |
67% |
|
Spa Primera |
28 |
25 |
1 |
2 |
89% |
Clearly Spain looks the best league with which to follow this strategy. Spain, like Scotland, has a very unhealthy two team domination and Barcelona or Real Madrid have won the league in all but 4 of the last 26 seasons. The Big 2 therefore have a strong advantage and that would account for these figures.
Looking at games poised at 1-1 as opposed to 0-0 we see
|
Div |
HT Draws |
Won |
Drew |
Lost |
Win % |
|
Eng Prem |
11 |
8 |
3 |
0 |
73% |
|
Ita Seria A |
6 |
5 |
1 |
0 |
83% |
|
Spa Primera |
10 |
9 |
1 |
0 |
90% |
Not a huge amount of data but a game that is already 1-1 looks more likely to go on to be a home win than a game that is goalless. I think this demonstrates that although the chance of a home win decreases slightly when a match is all square at half time, the odds more than make up for this and provide value.
Going back to the Real Madrid game I was watching; the game stayed at 0-0 despite Real Madrid having 25 shots. There are numerous occasions when you watch this type of game and the pressure the favourite exerts increases and increase before the smaller team cracks and I’d back Real Madrid in the same position again.
For the record these are all the teams that started at odds of 1.3 or lower and their performance when drawing at half time. I only included teams with at least 4 matches.
|
Team |
HT Draws |
Won |
Drew |
Lost |
Win % |
|
Real Madrid |
5 |
5 |
100% |
||
|
Barcelona |
13 |
12 |
1 |
92% |
|
|
Man United |
13 |
11 |
2 |
85% |
|
|
Arsenal |
4 |
3 |
1 |
75% |
|
|
Inter |
7 |
5 |
2 |
71% |
|
|
Milan |
3 |
2 |
1 |
67% |
|
|
Chelsea |
12 |
7 |
5 |
58% |
|
|
Juventus |
4 |
2 |
2 |
50% |
|
|
Liverpool |
5 |
2 |
3 |
40% |
Scoreless second half
A number of Betfair markets such as next goal, correct score and the over/under markets are affected by the number of second half goals. Let’s look at the chances of a scoreless second half by league.
|
Div |
Scoreless 2nd Half |
Matches |
% matches scoreless 2nd Half |
|
Eng Prem |
455 |
1900 |
24% |
|
Spa Primera |
434 |
1900 |
23% |
|
Ita Seria A |
432 |
1900 |
23% |
|
Total |
1321 |
5700 |
23% |
There seems little difference across these leagues and in general just under 1 in 4 matches has a scoreless second half. The next step is to see if the half time score affects that.
|
HT Score |
Scoreless 2nd Half |
Matches |
% matches scoreless 2nd Half |
|
0-0 |
455 |
1823 |
25.0% |
|
1-0 |
297 |
1229 |
24.2% |
|
0-1 |
165 |
846 |
19.5% |
|
1-1 |
137 |
591 |
23.2% |
|
2-0 |
99 |
392 |
25.3% |
|
2-1 |
46 |
202 |
22.8% |
|
0-2 |
33 |
193 |
17.1% |
|
1-2 |
22 |
117 |
18.8% |
|
3-0 |
20 |
89 |
22.5% |
|
2-2 |
13 |
55 |
23.6% |
The most interesting stat for me here is that a game that is 2-0 at half time is as likely to be scoreless in the second half as a game that is 0-0 and the chance is still 1 in 4. To investigate this further I dropped all matches with a strong favourite which I classify as teams priced at 1.3 or less using BbMxH (Betbrain maximum home win odds). In the Betfair data for 2009/2010 I was left with 66 games that were 2-0 at half time.
In these games I want to see what sort of profit would have been made backing the no goals being scored in the second half. A 2-0 half time game has a number of markets which are all the same such as 2-0 correct score, no next goal and under 2.5 and it’s the latter I will use as the data is easiest to deal with having just 2 outcomes and also better liquidity.
The full table showing all 66 results is produced at the end of the article. I looked for an under 2.5 goals price matched around 50 minutes after the start of the match. 20 of the 66 games went on to stay 2-0 and backing under 2.5 goals at the half time price I found would have returned a whopping 23 points profit which is an ROI of around 35%. The results also demonstrate the fluctuations that can happen in betting. If you started this idea on the opening Saturday of the season come Valentines Day you would have been in love with it, up 33 points and with an ROI of over 80%! The other people you told about it who started the day after might not have been so pleased with the 9 point loss they were saddled with to the end of the season. The same odds would no doubt be available for backing 2-0 as a correct score or no next goal.
In conclusion it looks like goals do not necessarily mean more goals although the perception of the general betting public is that it does.
Will they draw?
On a similar theme does the half time score affect the chance of the game drawing. Here is a list of scores and the chance of the game ending in a draw.
|
HT Score |
Ends in draw |
Matches |
% Chance of draw |
|
2-2 |
19 |
46 |
41% |
|
0-0 |
673 |
1745 |
39% |
|
1-1 |
206 |
564 |
37% |
|
1-2 |
30 |
116 |
26% |
|
0-1 |
194 |
830 |
23% |
|
1-0 |
223 |
1122 |
20% |
|
2-1 |
30 |
183 |
16% |
|
0-2 |
15 |
191 |
8% |
|
2-0 |
21 |
337 |
6% |
|
3-0 |
1 |
75 |
1% |
Quite clear if a game is a draw at half time then there’s a good chance of the final score being a draw. In this case what stands out to me is the fact that games that are 1-0 or 2-1 have a much lower draw chance and worth looking to see if laying the draw is possible.
In this case checking the Betfair data is not as easy as before as the data is only stamped as to when it first and last occurred. Therefore an odds value may occur in the first half, half time and the second half but it is not possible to know the half time value as only the first and last time the odds were taken is available without paying.
In this case I have looked at games where the away team started off as a favourite (BbMxA > BbMxH) to give myself an idea of the target odds.
|
Div |
FT Draw |
Matches |
% FT Draws |
Betfair Odds Required |
|
Eng Prem |
8 |
65 |
12.3% |
8.125 |
|
Ita Serie A |
8 |
59 |
13.6% |
7.375 |
|
Spa Primera |
7 |
49 |
14.3% |
7 |
It would be nice to prove this as a back or lay strategy but as the data does not allow it and it will have to be a watching brief.
Conclusion
The two clear messages that come out of this are firstly, that if a team are strong pre-game favourites the drift of odds in play can work in your favour. If I see Real Madrid again drawing at half time I will be happy to go in again and back them to win hoping that 25 shots will be enough this time! Secondly, goals do not necessarily mean more goals and if you want to stand out from the crowd go under as that seems to be where the money is.
Table showing Betfair in play half time odds for under 2.5 goals when the HT score was 2-0
|
Div |
Date |
Home |
Away |
First In Play Match |
Under 2.5 Match at HT |
Final Score |
Profit less 5% |
|
Eng Prem |
15/08/2009 |
Stoke |
Burnley |
1.78 |
3.8 |
2-0 |
2.66 |
|
Ita Serie A |
30/08/2009 |
Napoli |
Livorno |
1.88 |
4.3 |
3-1 |
-1 |
|
Ita Serie A |
30/08/2009 |
Sampdoria |
Udinese |
2.14 |
5 |
3-1 |
-1 |
|
Ita Serie A |
19/09/2009 |
Juventus |
Livorno |
2.18 |
5.7 |
2-0 |
4.465 |
|
Eng Prem |
19/09/2009 |
Aston Villa |
Portsmouth |
2.06 |
4.4 |
2-0 |
3.23 |
|
Ita Serie A |
20/09/2009 |
Sampdoria |
Siena |
2 |
5 |
4-1 |
-1 |
|
Spa Primera |
20/09/2009 |
Ath Bilbao |
Villarreal |
1.92 |
4.2 |
3-2 |
-1 |
|
Ita Serie A |
20/09/2009 |
Chievo |
Genoa |
1.77 |
4.4 |
3-1 |
-1 |
|
Spa Primera |
22/09/2009 |
Sevilla |
Mallorca |
2.28 |
5.3 |
2-0 |
4.085 |
|
Eng Prem |
26/09/2009 |
Tottenham |
Burnley |
2.72 |
5.7 |
5-0 |
-1 |
|
Spa Primera |
27/09/2009 |
Zaragoza |
Getafe |
2 |
4.1 |
3-0 |
-1 |
|
Ita Serie A |
04/10/2009 |
Palermo |
Juventus |
2.02 |
6.2 |
2-0 |
4.94 |
|
Spa Primera |
18/10/2009 |
Zaragoza |
Santander |
2.02 |
4.8 |
2-2 |
-1 |
|
Ita Serie A |
28/10/2009 |
Juventus |
Sampdoria |
2.02 |
4.3 |
5-1 |
-1 |
|
Eng Prem |
31/10/2009 |
Arsenal |
Tottenham |
2.74 |
5.4 |
3-0 |
-1 |
|
Eng Prem |
31/10/2009 |
Stoke |
Wolves |
1.74 |
3.9 |
2-2 |
-1 |
|
Eng Prem |
31/10/2009 |
Portsmouth |
Wigan |
1.82 |
4.3 |
4-0 |
-1 |
|
Ita Serie A |
28/11/2009 |
Udinese |
Livorno |
1.7 |
3.9 |
2-0 |
2.755 |
|
Spa Primera |
29/11/2009 |
Valladolid |
Tenerife |
1.95 |
4.1 |
3-3 |
-1 |
|
Eng Prem |
05/12/2009 |
Aston Villa |
Hull |
2.02 |
4.6 |
3-0 |
-1 |
|
Spa Primera |
19/12/2009 |
Ath Bilbao |
Osasuna |
1.71 |
4.3 |
2-0 |
3.135 |
|
Eng Prem |
26/12/2009 |
Man City |
Stoke |
1.94 |
4.4 |
2-0 |
3.23 |
|
Eng Prem |
11/01/2010 |
Man City |
Blackburn |
2.04 |
4.2 |
4-1 |
-1 |
|
Spa Primera |
16/01/2010 |
Osasuna |
Espanol |
1.59 |
4.1 |
2-0 |
2.945 |
|
Eng Prem |
16/01/2010 |
Everton |
Man City |
1.94 |
4.3 |
2-0 |
3.135 |
|
Ita Serie A |
17/01/2010 |
Roma |
Genoa |
2.1 |
4.8 |
3-0 |
-1 |
|
Spa Primera |
17/01/2010 |
Valencia |
Villarreal |
2.14 |
5.3 |
4-1 |
-1 |
|
Ita Serie A |
24/01/2010 |
Genoa |
Atalanta |
1.93 |
3.95 |
2-0 |
2.8025 |
|
Ita Serie A |
24/01/2010 |
Palermo |
Fiorentina |
1.8 |
4.2 |
3-0 |
-1 |
|
Eng Prem |
27/01/2010 |
Everton |
Sunderland |
1.99 |
5 |
2-0 |
3.8 |
|
Eng Prem |
31/01/2010 |
Man City |
Portsmouth |
2.14 |
4.5 |
2-0 |
3.325 |
|
Spa Primera |
06/02/2010 |
Valencia |
Valladolid |
2.46 |
5.3 |
2-0 |
4.085 |
|
Eng Prem |
06/02/2010 |
Stoke |
Blackburn |
1.68 |
3.45 |
3-0 |
-1 |
|
Ita Serie A |
07/02/2010 |
Inter |
Cagliari |
2.26 |
5.7 |
3-0 |
-1 |
|
Eng Prem |
07/02/2010 |
Chelsea |
Arsenal |
1.95 |
4.2 |
2-0 |
3.04 |
|
Eng Prem |
09/02/2010 |
Fulham |
Burnley |
1.73 |
4.8 |
3-0 |
-1 |
|
Ita Serie A |
13/02/2010 |
Sampdoria |
Fiorentina |
1.78 |
3.9 |
2-0 |
2.755 |
|
Ita Serie A |
14/02/2010 |
Cagliari |
Bari |
1.8 |
4.5 |
3-1 |
-1 |
|
Spa Primera |
21/02/2010 |
Ath Bilbao |
Tenerife |
1.93 |
5.7 |
4-1 |
-1 |
|
Ita Serie A |
21/02/2010 |
Cagliari |
Parma |
1.96 |
4.2 |
2-0 |
3.04 |
|
Ita Serie A |
21/02/2010 |
Palermo |
Lazio |
1.87 |
3.6 |
3-1 |
-1 |
|
Ita Serie A |
27/02/2010 |
Catania |
Bari |
1.71 |
3.7 |
4-0 |
-1 |
|
Ita Serie A |
28/02/2010 |
Milan |
Atalanta |
2.24 |
4.8 |
3-1 |
-1 |
|
Eng Prem |
28/02/2010 |
Tottenham |
Everton |
1.82 |
4.2 |
2-1 |
-1 |
|
Spa Primera |
07/03/2010 |
Ath Bilbao |
Valladolid |
1.92 |
4.3 |
2-0 |
3.135 |
|
Eng Prem |
20/03/2010 |
Sunderland |
Birmingham |
1.72 |
3.75 |
3-1 |
-1 |
|
Spa Primera |
20/03/2010 |
Xerez |
Tenerife |
2 |
5.3 |
2-1 |
-1 |
|
Eng Prem |
28/03/2010 |
Liverpool |
Sunderland |
2.3 |
6.6 |
3-0 |
-1 |
|
Spa Primera |
28/03/2010 |
Villarreal |
Sevilla |
1.99 |
5.4 |
3-0 |
-1 |
|
Spa Primera |
28/03/2010 |
Xerez |
Valladolid |
1.74 |
4.4 |
3-0 |
-1 |
|
Spa Primera |
03/04/2010 |
Sevilla |
Tenerife |
2.36 |
4.4 |
3-0 |
-1 |
|
Ita Serie A |
03/04/2010 |
Catania |
Palermo |
1.69 |
4.7 |
2-0 |
3.515 |
|
Eng Prem |
03/04/2010 |
Sunderland |
Tottenham |
1.98 |
4.7 |
3-1 |
-1 |
|
Ita Serie A |
11/04/2010 |
Roma |
Atalanta |
2.48 |
4.9 |
2-1 |
-1 |
|
Spa Primera |
11/04/2010 |
Ath Bilbao |
Almeria |
1.96 |
4.6 |
4-1 |
-1 |
|
Spa Primera |
11/04/2010 |
Mallorca |
Valencia |
2.02 |
5 |
3-2 |
-1 |
|
Eng Prem |
17/04/2010 |
Sunderland |
Burnley |
2.24 |
5.2 |
2-1 |
-1 |
|
Spa Primera |
17/04/2010 |
Villarreal |
Ath Madrid |
2.42 |
5 |
2-1 |
-1 |
|
Eng Prem |
17/04/2010 |
Tottenham |
Chelsea |
2.12 |
5.9 |
2-1 |
-1 |
|
Eng Prem |
19/04/2010 |
Liverpool |
West Ham |
2.02 |
4.7 |
3-0 |
-1 |
|
Eng Prem |
24/04/2010 |
Bolton |
Portsmouth |
2.1 |
4.8 |
2-2 |
-1 |
|
Ita Serie A |
24/04/2010 |
Palermo |
Milan |
2.08 |
5.1 |
3-1 |
-1 |
|
Spa Primera |
25/04/2010 |
Ath Madrid |
Tenerife |
2.1 |
5.9 |
3-1 |
-1 |
|
Eng Prem |
01/05/2010 |
Birmingham |
Burnley |
1.91 |
4.4 |
2-1 |
-1 |
|
Spa Primera |
08/05/2010 |
Villarreal |
Valencia |
2.6 |
6.4 |
2-0 |
5.13 |
|
Ita Serie A |
15/05/2010 |
Milan |
Juventus |
2.38 |
6 |
3-0 |
-1 |
|
|
TOTAL |
23.21 |
|||||
|
AVERAGE |
2.02 |
4.73 |
0.35 |