Below is an attachment which will form the basis for the 2011/12 Systems Reviews.
This attachment should be looked at in conjunction with the blog postings over the next week or so. Once all individual system reviews are carried out, they will be included on a single page on the blog entitled Systems Reviews 2011/12. I hope to do the system reviews over the next week or so, so keep reading the blog.
Key things to remember when using data like this are:
· The historical results aren’t meant to be an indication of future profitability. Yes, the systems are built looking at historical results but one season of proofed results is worth 100 seasons of backtested results. Hence, place much more weight on live results.
· Don’t worry too much about the fact the performance appears to worsen over time on many systems. It is the way the systems are built. Other services tweak the ratings and systems after every season and then restate the backtested results. This isn’t happening here, so the live results are really live results and not backtested results after tweaks to the systems! Put simply, there are many systems that look great during backtesting and backfitting but fail when they go live. These systems (touch wood) have shown they work live and will hopefully continue to do so.
· Analysing backtested/live results may help you spot potential weaknesses in the rating algorithms or systems but be VERY careful about increasing or decreasing stakes based on a certain criteria unless it is based on a large sample of live data. IMO, a large sample needs to be hundreds of bets, possibly thousands of bets. If you start interfering with the system bets and trying to cherry pick a certain type of selection, you are likely to decrease your chances of winning long-term.
· Don’t buy into trends too much as it is only a trend, not a guaranteed change. Hence, a league which may be the best season one season may be the worst next season. Likewise, a league which is losing one season may be winning next season. Don’t fall into the trap of backfitting your own portfolio to follow!
· Be careful about writing off the Asian Handicap returns as clearly, when you see the graphs compared to the outright returns, they are nowhere nearly as good. However, for a subsection of bets, it may be the case that AH can smooth your returns. Then again, they may not!
· There are very minor data issues apparent within the data. With any large sample of data, there can be small discrepancies thrown up within the data. As far as I am aware, none of the issues are material or even close to being material. For example, a Premiership Away bet may have slipped onto a system even though they were not to meant to appear on that system. I know why (Premiership was spelt incorrectly for that bet!) but all bets stand as given. Likewise, I’ve put the odd bet on 6-21 last season even though it didn’t appear on 21 as it was dropped due to a price change at the last moment. Things like this aren’t material!
OK, without further ado, here is the attachment for you to download.
The spreadsheet is 9MB in size and therefore, may take a while to download depending on your connection speed. The two sheets with the actual data in it (I’ve pasted it in this overall sheet as values!) were about 100MB in size!
If there are any questions, post them up here or comment on the individual blog posts. If people spot a glaring error within the data, please email me at firstname.lastname@example.org and I’ll take a look at it!
Once the system reviews are completed, I’ll tidy up the data sitting behind the analysis and I will be sharing the historical results with all members of the 2012/13 season. This data will NOT be shared with non members. The purpose of the additional data release is to help Excel savvy members do their own analysis to help form a view of systems to follow for next season. Those without the Excel skills required can rely on my help this Summer as promised!
I also meant to say that there are 160 tables showing the profitability of all 20 systems, split by season, league, season and league, by month, by Home and Away, by Home and Away and Season, by League and Home and Away, by Season and League and Home and Away. It also shows the profitability of backing outright, using AH0, AH0.25 and AH0.50.
There are also 120 graphs in here too for those that like pictures, showing P&L since inception, P&L live and drawdowns for each of the 4 methods of betting.
I appreciate that this isn’t everyone’s cup of tea but then again, I hope some of you appreciate the time and effort that goes into producing something like this. :)