Posts

Does time of shot affect affect xG?

A major decision for managers of smaller clubs, who can’t just blow opposition teams away, is whether to go out quick at the start and try and get an early lead, then defend it or to keep it tight, before throwing everything at the wall for the last period of the match to try and snatch it at the death. Both methods have their benefits; the early attack gives more time to get the goal, but there’s no definitive end point as to when to start shutting up shop if the goal can’t be found as it’s unlikely a team would be able to keep up the intensity for a whole match. The late attack gives you more defensive security, as you prioritise not conceding in the early stages but can backfire if your opposition is fitter and have more in the tank at the end. What if it was possible to tell when is best to attack based purely on xG, if it could be shown that the time in the match affected how likely a shot was to be scored? It could help to decide when to attack to get the most out of it, or wh...

Huddersfield’s Possesion Problem

A link back to a thread I posted after the Cardiff game but seems still very relevant today https://twitter.com/colosslvictory/status/1034196536438087680 . We can't beat teams that sit deep and don't try to play, never have under Wagner and seemingly still can't. These teams turn up with a game plan to get a point and more often than not we are kind enough to give them all 3 for the troubles. The main problem is the pressing isn't as effective against them as they not only have the ball less so less opportunities but when mistakes are forced there is no space in behind to exploit and this leaves us out of options as we don't have a good enough delivery or patience to break these teams down. This also was a problem for Liverpool last season, although obviously not as badly), who also play the pressing game and they had a really hard time breaking down deep sitting opposition (H v Stoke, H v West Brom, A v Newcastle ) but this season they seem to have found a way ...

Premier League Predictions 17

Week 13-16 Review - Week 13 - 3 results with 1 score and unfortunately a most confident wrong, bad week overall Week 14 -  5 results with 2 scores and both most confident right, a good week as hitting target Week 15 -  6 results with 1 score and both 'bankers' right, good week as above target would like more scores though Week 16 -  4 results 1 score and both 'bankers' right Overall a fairly good set of results running only slightly below target for number of results, hoping to see a continued improvement as more data becomes available and thus it can be trained more. On the betting front it has fallen quite far down to -£5.60 overall loss (so £160 bet so far and still have £154.40) for the season so could be better. Week 17 Predictions - I can't get the graphic to work again so here is a table, unfortunately this means the predicted GD has been excluded and it is just the results. Home Predicted Score Away Most Confident ...

Premier League Predictions 13

Week 12 Review - A slight improvement this week and edging closer to the target of half of the results correct a week. This week the predictor got 4 correct results, 3 of which were correct score lines as well which is a shockingly high proportion. Once again we were denied a correct result (& score) in the early kick off by a 90+ minute goal, the early kickoff starting to become unlucky. This takes the tally to 58 results with 11 of them being correct scores. We also lost more money on the betting system this week as the results got were mostly straightforward with quite high odds for success (Man C, Liverpool, Spurs) and are now at a £.120 loss for the season. Week 13 Predictions - I can't get the graphic to work this week so here is a table, unfortunately this means the predicted GD has been excluded and it is just the results. Home Predicted Score Away Most Confident Brighton 1-1 Leicester Everton 2-1 C...

The problem with xG totals

There has been several reports in the media suggesting that despite Town’s impressive first half performance against West Ham they were in fact lucky to get a point in the end due to a number of high quality chances given away. Now when you look at the xG totals from the game it would seem to back this theory up with the xG score being: 1.19-2.04. The only problem here with these totals is that they take all context out of the individual chances when summing them up, it assumes all chances are independent for the relation to hold. Take Hernandez’s double chance just after half time where he takes a shot from close range which is saved before putting a header over the bar. Now he generates an xG of 0.49 and 0.57 for these two chances respectively, which would suggest that he has a 22% chance of not scoring, 50% chance of scoring once and a 28% chance of scoring twice. Although this can’t be true because how could he have scored two goals in that time there was only 1 second between ...

Premier League Predictions 12

Image
Week 11 Review - So all in all not the best first week to post about with just 3 correct results including 1 correct score. The 7 draws predicted did manage to catch the only draw of the weekend but  unfortunately for the predictor lots of teams who had been going through bad spells decided to show up; Newcastle, West Ham and Huddersfield (a result I am very pleased about though). This takes the tally to 54 results with 8 of them being correct scores. The bad week also means that we lost hypothetical money and are now down to £1.27 in profit over the course of the season - the Arsenal-Liverpool game making most of the difference to keep it in the green. Week 12 Predictions - The information in the central column is the predicted scoreline followed by the predicted goal difference. This week we have a much more even spread of results with 5 home wins, 2 draws and 3 away wins. Unsurpisingly the two most confident results are Liverpool and Chelsea at home to Fulham and E...

Premier League Predictions 11

Image
Each week I am going to try and remember to post my ML premier league predictor's predictions for the round of fixtures and keep track of how well it is doing in terms of correct results and scores. I will also be including a track of money won and lost if each predicted result was bet on. This will be done using my v2 for now but will transition to v3 when it is complete. I am starting 10 weeks in to the season as most teams have now played 5 home and 5 away games and thus the attributes fed to the machine learning algorithm should be fully populated and give more sensible predictions. Due to the way it is set up in very early weeks attributes like form can behave weirdly if a team has 0 points and another max even if it has only been 1 game. For comparison, so far the predictor has 51 results correct of which 7 of these have been correct scores. Betting £1 on each game's predicted result would have yielded a profit of £5.01 so far not including stake. Week 11 Prediction...