Wednesday, April 27, 2011

Live Chat as requested - Tonight at 21.00

Saturday, April 23, 2011

Do Hot Streaks Exist?

Interesting analysis from fangraphs suggesting that just because a player is in a hot streak, there is no evidence it will continue. However, this analysis looks at aggregated player data - within that there will be some players who continue to be on fire, and some who cool down. No idea how you pick the right ones but maybe you just grab anyone who is hot, and cut them if they start to suck.

Friday, April 22, 2011

Fixing the Yankee problem

Bud Selig's latest genius idea is to expand the playoffs to 10 teams as soon as 2012.

Quoting Da Grizzlies: "Apparently that fool Selig is '“working on” adding two teams to the playoffs and we could see changes as soon as 2012' - ten out of thirty teams is way too many, especially with the stupid spread-out playoff series that allow you to get away with only two good pitchers."
Whilst Bud Selig is a man of terrible ideas, this is a solution to the 'problem' of the AL East being stupidly difficult to win because it contains the 2 richest teams in baseball - at least it would give the team finishing 3rd in the AL East a chance at winning the wild card. Alternatively, we could trust in the abilities of smart people running smaller franchises like the Rays and cheer when they beat the odds to reach the World Series, because it can happen.

Or, we could get radical.

Radical Solution 1:
My first suggestion is to contract the Yankees. This would instantly make the AL East fairer, giving the Blue Jays and Orioles a fighting chance of winning the wild-card. It would also bring about the end of obnoxious Yankee fans, Yankee exceptionalism, Jeter Hagiography, pink Yankee hats, that stupid 'got rings t-shirt, and boring Yankee games on Sunday night baseball. But I guess this solution may not be popular with everyone.

Radical Solution 2: 
Alternatively, the Yankees and Red Sox could play each other 162 times a year to decide home field advantage for the 'world series' (all games broadcast exclusively on Yankee and Red Sox TV). The rest of baseball will continue to play each other for the World Series with the addition of two expansion teams in cool places (Alaska and Hawaii might be fun) taking the place of the AL big two. The winners of the 'world series' can play the winners of the World Series, and should the Yankees or Red Sox win, their fans can pretend they truly are World Champions.

Or, more sensibly, there could be a salary cap, preventing the Yankees and Red Sox outspending everyone else and/or the addition of a Connecticut or New Jersey Team (The Jersey Shore?) to suck up some of the Yankee and Red Sox revenue, along with some kind of re-alignment resulting in 2 NL and 2 AL divisions (or no divisions, just an AL and an NL), with 8 teams making the play offs, as now. Oh, and while we're improving baseball, let's get rid of the DH. And bunting.

Tuesday, April 19, 2011

Time to replace K/9 with K/Batter faced

An interesting critique of K/9 from fangraphs: http://www.fangraphs.com/fantasy/index.php/james-shields-and-using-k/. Paraphrasing, you can have a really good K/9 but awful ERA/WHIP if you give up lots of hits and walks, but also strike out everyone who you don't walk or let hit you (e.g. James Shields). So maybe it is time that fangraphs modified FIP/WAR to take this into account?

This is also relevant to these posts

Shoplifters of the World Unite

Reds right-hander Mike Leake was arrested Monday at a downtown Cincinnati Macy's after attempting to leave the store with nearly $60 in merchandise:

http://hardballtalk.nbcsports.com/2011/04/19/following-up-on-the-mike-leake-arrest/

Reminds me of this:

'No one could quite believe a bloke like him, with all that money, would be moronic enough to nick a toilet seat'

http://www.guardian.co.uk/football/2007/jan/19/newsstory.sport3

Tuesday, April 5, 2011

FIP: A thing that is better than ERA at predicting future performance



This is a continuation of previous posts looking at how predictive different pitching metrics are. To estimate this, I plotted the relationship between a stat in year one versus ERA in year two, and calculated the R^2 value for the line of best fit - for a detailed description of the method, check here. The R^2 value for ERA in year 1 vs ERA in year 2 is 1.3 - therefore for a stat to be better at predicting future ERA than ERA itself, the R^2 value must be > 1.3. The stats analysed are those most commonly referred to by fantasy baseball tipsters to suggest which pitchers you should pick up because they are good, and who you should avoid because they are just lucky.

If you are interested in K:BB ratio, check here

EDIT and here is the first of these articles from 2011. They use xFIP to assess pitcher performance over an incredibly small sample size. Read on to find out if that is a good idea.

If you want to know what is better than ERA at predicting future ERA (e.g. an R^2 > 1.3) read on:

Whilst FIP may be not very fair to the 'lucky' pitcher when calculating WAR, it is the best metric we have to estimate future pitching performance. Check the graph.

Whereas the other metric beloved of fangraphs loving fantasy baseball experts, xFIP, is barely better than ERA at estimating future performance:

So, in summary: If you want to use stats to guess a pitchers future performance, use FIP, not ERA. But it isn't perfect - an R^2 of 0.2 isn't that high. Furthermore, it's actually quite easy to out-perform FIP - in the next graph for each qualified starter I've calculated ERA-FIP, and then plotted the average for all qualified starters by year. In this case, a negative number = outperforming FIP - as you can see, on average a starter will outperform (have a lower ERA) than FIP.





And finally here is a table of pitchers who've been qualified starters each of the last 3 years, showing how often they've had an ERA outperforming FIP.




What does this mean? Well, those pitchers who've had a better ERA than FIP for the last 3 years will probably carry on outperforming their peripherals and those who have a better FIP than ERA will probably continue to under-perform their peripherals - but this doesn't matter too much as Tim Lincecum and Justin Verlander are still pretty good, even if they aren't as excellent as they 'should' be. The bottom line is that FIP is the best stat for predicting future performance, so you should be interested in pitchers who's FIP is better than their ERA. But it isn't perfect, and there are many pitchers who will have better or worse results than their FIP suggests.