Jump to content

Welcome to One Team in Bristol - Bristol City Forums

Welcome to One Team in Bristol - Bristol City Forums, like most online communities you must register to view or post in our community, but don't worry this is a simple free process that requires minimal information for you to signup. Be a part of One Team in Bristol - Bristol City Forums by signing in or creating an account.

  • Start new topics and reply to others
  • Full access to all forums (not all viewable as guest)
  • Subscribe to topics and forums to get email updates
  • Get your own profile page and make new friends
  • Send personal messages to other members.
  • Support OTIB with a premium membership

JEP

Newbies
  • Content count

    11
  • Joined

  • Last visited

Community Reputation

65
  1. Some of you might remember my post from earlier on in the season, where I compared not only our results after 11 games from both this season and last season, but also against the same teams home or away. Assuming every team improves over the summer transfer window, combining the two works as a nice way to see our what our performance is like this season relative to last season. I've kept the spreadsheet updated, and now seems a fairly nice time to post it, given we're now halfway through the season. I don't need to say how well we're doing, since that's fairly obvious, but it's nice to see just how far ahead we are on both fronts with massively improved goal differences too. I think it's also interesting that we can't seem to beat Preston at home or Birmingham away. Gaining points from the return fixtures - regardless of how well the teams are doing at the time - would be great. I'd love to see all the number in the gold column on the right, with either 0s or positive numbers in at the end of the season! Again, I'll keep this updated and post again in 10-12 games time for another comparison, and as ever I welcome all your comments. Have a great Christmas everyone!
  2. "In Form Bristol City"

    Thanks for the comments everyone. I've uploaded this and my other two posts on the forum to here: http://statsandbcfc.blogspot.co.uk/ which I'll post to (as well as here) as and when I come up with my next bit of work. As a bonus image, here are all the averages stuck on the same graph. I've been compiling our results since June for the other couple of posts that I've done, so that part doesn't take too long. The moving averages was just a case of working out the best Excel formula to use to for the whole 43 game blocks - doing it manually for 3 or 4 is fine, but it would have been incredibly time consuming to do that for all of them! Creating the graphs and the gif took a couple of hours. I have access to MATLAB at work, which is what I used to create the graphs. I played around with it after I finished on Friday to try and get all the background information put on in the right place, then you create all the graphs at once, stick them on top of one another and that creates the gif! As being an Analyst is my day job, it's quite nice to put what I do at work to something that I find really interesting; and it's self-feeding loop, in that I taught myself a couple of programming things to make this which will probably come in use down the line at work. I'll happy deny that I am Mark Ashton, due to the lack of a mention of DNA in my posts!
  3. "In Form Bristol City"

    TL;DR: I've taken a look at our form in the 79 league games since LJ took charge, from 3 games to 46, to see how often our current form has been repeated. It hasn't been repeated, and we are currently achieving the best patch of results since he took over, which is fantastic. You can also see how bad our run of results last Christmas was, and how it's affected our long-term points average, it's something that we've only just started to recover from - statistically speaking. __________________________________________________________ When driving home last week, I was listening to 5 Live, and at a break between the Roma v Chelsea game the commentator said something along the lines of, “And there’s been another goal at Craven Cottage, which way has it gone?” It then cuts across to the reporter who then says, “it’s another goal for in form Bristol City, 2 nil!” After the celebratory tap of the steering wheel, I kept thinking, “In form? But in our last three league games, we’ve only won once and that was away at Sunderland; and we were awful against Leeds!” That has inspired this post. What do we mean by “in form Bristol City?” Is it how we perform over three games? Six games? Ten games? Or even twenty? To do this, I’ve taken a moving average of the points per game (PPG) of every result since Lee Johnson took charge of City, scaled to the number of points we would get at the end of the season. This is to see at when we have performed best and worst (10 points if you can tell me when that was!) over a given period of time. I’ve taken this moving average from 3 to 46 games, to get a really good spread of “form”. I’ve made graphs for all of these, that also include: Promotion points over the last couple of seasons Playoff points over the last couple of seasons Relegation points over the last couple of seasons Markers for the maximum and minimum numbers of projected points we’ve achieved Rather than post each individual graph to here and have an overly long thread, I’ve made this gif that cycles through all the graphs, so you can see what happens as you add more games to the moving average. Along the x-axis is the number of league games we’ve played since LJ took charge. The y-axis shows the projected number of points we’d obtain over the season, if we maintained the points per game from the group of games selected. For example: The MA6 graph is a moving average of 6 games. If you get WWWWWW, you average 3 points per game and would get 138 points throughout the season. If you get LLLLLL, you would average 0 and get 0 throughout the season. After losing 6 games, you may win, so your form would be LLLLLW, giving you 3 points from 6 games. An average of 0.5 points per game. Having this over the season would mean you would get 23 points - still you would get certain relegation! To read these off the graph, find a game number on the x axis. This is the middle game in the set of games if the group is an odd number: Reading game 35 on the MA3 graph gives the average for games 34, 35 and 36 Reading game 35 on the MA6 graph gives the average for games 32, 33, 34, 35, 36 and 37. You can scale this up to 46 and this is why the graph shrinks as the MA goes up towards 46. When this season finishes, the MA46 graph would move up to halfway through this season. All of the graphs are in this album linked below, so you can have a proper look if you want, but the gif I’ve posted shows all of them in increasing order of games. I’ve also stuck all the results onto the end of the album. https://imgur.com/a/2uuH8 So what should you be looking out for? Some of the key points to notice when looking through them: The most obvious thing is that there’s a 20 game period, between 30 and 50 games, that not only includes “the run” but many games either side of it where we weren’t picking up many points, or how long it took for us to get out of the slump. After the MA6 graph, the maximum value hugs the right hand side and rarely changes from there, this implies that our best form is most recent. You can’t tell form from 3 games, as I tried to when listening to the radio. It changes so much that you can’t build a proper picture from it. I like the Gary/Lee Johnson method of look at 10 game blocks. That’s enough time to get a good feel for what’s happening and you can see from the graph that it’s just starting to smooth out - that’s getting rid of the variability that you get from the 3 game moving average. So to summarise: Without trying to open a can of worms, the run last season was that bad. However, given LJ has now been in charge for 79 games, a 20 game period of really bad form has in part, overshadowed all the good work either side of it, pretty much until now. City are now achieving their best results since LJ took charge - that is obvious. Not only over the last 5 or 6 games, but the last 20, 30 and 40 games. Our form in the last 12 games would see us as champions over the last two season and our form in the last 20 games would be enough to get us into the playoff for the last two seasons. The purpose of this was to take a quick look at our ever changing fortunes since LJ took charge. Hopefully you might look at the blocks of form, the 3-6, game periods that change massively over the course of the season (unless you're at the very top or bottom of the league) and think that it's only when you get towards 10-15 games that you get a real picture of how we're doing. Coincidentally, we're 16 games into the season and looking very, very good. Whilst this doesn't tell us anything new, it reaffirms what we've been thinking about how we're doing this season. I think that "In Form Bristol City" could quite possibly be here to stay for the whole season.
  4. The comparison to last season

    I think in order to get the whole picture you need to look at both of them together and not separately. Yes, we have had the same start as last season as @glos old boy, but the games that we've had have been tougher than those last season, so I think we do have reason to be a little excited. If that 7 is there all season, then we'd finish on 61 points, something which I think a lot of us would have taken at the start of the season - though probably not now!
  5. Disclaimer: I've put this spreadsheet together over a couple of hours this evening, so I'm sorry if I've got anything wrong! Something I'm interested in is comparing how we did last season to this season, both in terms of the first 11 games we've played, but also against the equivalent teams from last season. The spreadsheet I've attached shows our results from last season put next to our results/fixtures from this season. The red box in the corner shows the points, goals scored, conceded and goal difference in the 11 games that we played this season and last season. It also shows how we performed against the same teams last season. I've put the relegated teams from the Premiership equal to the teams that went up last season, and the teams promoted from League One equal to those relegated to it. The key thing to take away from this is that we're 7 points better off in the same fixtures as last season, scoring 7 more and conceding 5 less. I'll try and keep this updated for the rest season and post the updates at various points over the coming months.
  6. So, Taylor Moore....

    If the long term goal is to play him at right back, is Pisano's age not perfect to phase him out and Moore in the next few years?
  7. Relative Importance Values 2016/17

    They must do. Just had a search on the club's website for "Analyst" and they were recruiting for first team analyst last summer. Link here. A couple of interesting things from the link: The first team analyst is part of the analysis department and reports to the head of analysis - meaning they should have a group of people doing this. To add to this, I'd be very surprised if they didn't already know what I posted at the top of the page A quick google of Scout7 looks like it is some massive player database, which must make data collection and analysis a whole lot easier. The candidate also needs to be able to use Prozone, so there's that too. 4 or the 5 requirements are directly sports/football related rather than statistics (with the 5th being a driving license), which rules me out for ever getting the job!
  8. Relative Importance Values 2016/17

    Thanks everyone for the feedback - I'm glad you've found it interesting! I think Taylor's score is inflated slightly due to him only starting 9 games since arriving, but we picked up more points in those 9 games than we did relative to the rest of the season so his presence really did have a positive effect on the team. With that in mind, I think he could be an important player for us next season in the 10 role, replacing Tomlin. I wouldn't be surprised to see him take over that shirt number too. That's my understanding too. Tomlin's score of just under 1 means that we performed pretty much as well in the games that he started in than the games that he didn't. It will be interesting to see whether, should Tomlin leave this summer, he has a similar indifferent impact on his new club next season. On the topic of Little I agree, he did excellently for us last season in the role he was given. The graph also highlights actually how much better he did than our other right back options. What I imagine has happened is that Little has left for first team football (and he deserves it) because he would be a more than capable back-up right back for us and I'm sure the management would feel that too. Thanks Dave. It occurred to me about halfway through collecting the data that I should have included the times that players were subbed, but was too lazy to go back and start again! I might go back and take another look when I'm bored next. Similar to that, I've been creating some squads representing our most common starting lineups at various points in the season. I'll post them up when I've got them in a format I'm happy presenting!
  9. Although this is the first post on this account, many years back I was registered on here as @JoeCityFan and visit the forum pretty much daily as a reader. I’m a City fan and a maths analyst so as it's the off season and I was bored at the weekend (and inspired by the book Soccermatics by David Sumpter), I thought I'd take a quick look over our results in the hope of finding out something reasonably interesting. The result of this is what I've called a player's Relative Importance Value - (RIV), ie to see if we have performed better when starting with a particular player or not. To do this I used the ratio between the points gained per start of a player and the points per missed game*. You could compare two players by comparing their points per game values (PPG), but there is no way to understand how the team performed when those players weren't playing. If Player A achieves a PPG of 1.2 and Player B achieves 1.1 PPG, then we would say that the team did better when Player A played. Though, if the team achieved 1.4 PPG when Player A did not play and 0.8 PPG when Player B did not play, we could assume that Player B was a more integral part of the side than Player A. The most basic interpretation of the RIV score is if a player's score = 1, then the team performs equally as well when the player starts and does not start. A value greater than 1 indicates that the team achieves more points when this player starts; and a value less than 1 indicates the opposite, so the team performs worse when the player starts. My interpretation is that when the score is high, a player fits into the system that the manager picks and the team benefits. A low score indicates not necessarily that the player is bad (it may be in some cases) but they do not fit, or work well in the system that has been picked. Some caveats though. This formula is very basic and I really do appreciate that there are multiple levels of complexity that can be added to give a better overall picture of the squad. An assumption I've made is that substitutions do not affect the outcome of the match and essentially we live and die by the team that kicks off. Of course, in reality this isn't the case and substitutions do occasionally have an effect (Rotherham at home?) and it's something that I'd like to investigate further. Something else you'll notice from the graphs is the lack of any bar for Aden Flint. This is simply because he played every game, which means there isn't anything to divide his points per game by. Results On to the results. I've uploaded a couple of graphs to the link below. The first is a graph ranking the players by their RIV score and in the second I've tried to group them by position and then rank them. http://imgur.com/a/6uEd3 Note: Engvall and McCoulsky are there because their squad numbers were between some of the other players' numbers. Djuric's bar is blank because we lost the three games that he started in. Are the results what you might have thought? Generally most of the graph is as expected, especially with Giefer and Adam Matthews down the bottom! Interestingly our most effective performers are Matty Taylor and Jamie Paterson. If you remember in the short amount of time that Tammy didn't play, we didn't fare too badly, which is reflected by his score of 1.2. A few other things to note · Pack and Smith score highly. Smith started 14/21 games in the same side as Pack, so I believe there is a relationship between their scores. Smith's score could have been brought down by him not starting those 7 games alongside Pack. · Fielding may be shaky, but he's no Giefer! · The general improvement with Wright in defence over Magnusson. · Bobby Reid, Callum O'Dowda and Zak Vyner are not starters at the moment and Wilbs might be more suited to off the bench appearances! · The performance of the side is very slightly better when Tomlin does not start. · Hopefully we'll find a place for Hegeler to fit next year. · Joe Bryan with a score less than 0.8?? The Curious Case of Joe Bryan On the back of that bullet point, I tried to work out why Joe Bryan's score was so low, since this is a player who has started the majority of games this season (39) and allegedly been scouted by Premier League clubs. Surely he must be more important to us than that? It occurred to me that he is probably the only player in the side whose position is split between two: left back and left midfield. I've gone back through all of the starting lineups to find the games where I've assumed him to have started at left back or left midfield. The result is the following graph: http://imgur.com/Xhk7MmS The difference between the performance of the team in Joe's two positions is pretty clear. We seem to struggle when he plays in midfield but his importance at left back puts him third in the overall squad ranking (ignoring Flint!). Summary The RIV is a measure of the effectiveness of starting particular players. It isn't affected by the strength of the opposition squad, the subs made or the overall context of the match. In that sense it is very basic. Though it is not a coincidence that the top players in the squad are those that finished the season so strongly, it is interesting to see the positive effect that Matty Taylor and Bailey Wright had on the club and the performances of the team. Hopefully this little bit of analysis has been interesting. I look forward to reading, replying and learning from your thoughts. I'm happy to send the data file I've created to anyone who wants it, since it's all open sourced from the BBC website; and if there's anything of interest that I can post then request and I'll let you know if I can do it! Joe *The Method (if you're interested in how I calculated each player's RIV) I've been through the team selection (from the BBC match reports) for every league match this season and noted the number of points earned by the players who have started, divided this by the number of games they've started to find their points gained per start. Then I've found the difference between the total number of points City achieved and the number of points that player has achieved and then divided that by the number of games they didn't start in. The ratio of these two numbers is the RIV. For example: The team earned 35 points in the 30 games that Lee Tomlin started. 35/30 = ~1.17 points per start. This then means that we got 19 points in the 16 games he didn't start. 19/16 = ~1.19 points per missed game. RIV = 1.17/1.19 = 0.98
×