TomG's Robot Professional MLB Betting

[bigalt]

you can probably back-test this system using season averages.

it would most likely give you better-than-true results because the stats from the games in question contribute to the average that you're using, but if that fails you at least know you're barking up the wrong tree.

[WaterOlay]

[ QUOTE ]
Updated YTD:
19.51 units wagered
+1.89 units
+9.7% ROI

Sunday Baseball...
St. Louis at Detroit
St. Louis +178
Risk 1 unit to win 1.78 units

Two new pitchers. Let's call it a wash.

[/ QUOTE ]

verlander has been in mlb for 3 years

[TomG]

[ QUOTE ]
Season to date for offensive power ratings seems fool-hardy.

That methodology would've had you projecting ARod as a guy who hits 80 HRs not that long ago when everyone knew he probably wasn't even going to get over 50 even with the big head start.

[/ QUOTE ]
It is a fair point especially this early in the season. In the example you gave, right now ARod accounts for nearly 20% of NYY's total offensive power rating (a player's fair should would be 11%). So his hot start is skewing things upward for NYY. I have my own ideas for an improved model that would likely use batting stats from the previous season and current season to date.

[TomG]

[ QUOTE ]
[ QUOTE ]
Updated YTD:
19.51 units wagered
+1.89 units
+9.7% ROI

Sunday Baseball...
St. Louis at Detroit
St. Louis +178
Risk 1 unit to win 1.78 units

Two new pitchers. Let's call it a wash.

[/ QUOTE ]

verlander has been in mlb for 3 years

[/ QUOTE ]
Whoops thank you for that. He has a historical xERA 4.34 and season xERA of 2.76. I gave him an xERA for this game of 4.28. Is Brad Thompson much worse/better than that? I don't think his initial numbers indicate too much difference, so fortunately I still like St. Louis pick.

[WaterOlay]

[ QUOTE ]
I still like St. Louis pick.

[/ QUOTE ]

me too [img]/images/graemlins/smile.gif[/img]

[TomG]

Here is a question that I don't know the answer to... maybe someone can help. How much of a direct comparison is there between bullpen xERA and the starting pitcher's xERA? For example, let's say a pitcher is starting his 3rd game after spending a few years in the bullpen with an average xERA of 3.0. How bad is it to use his bullpen stats as an indicator of his performance as a starter?

[macavity]

Tom,

I appreciate this question is slightly redundant given your comments about working on an improved model but could I ask for some clarification on the exact method you've been using to date to generate the offensive power ratings?

Let me be upfront and say I'm a relative newcomer to both baseball and baseball betting but I picked up Michael Murray's book a few weeks ago and have just got round to trying to put his method into practice (in much the same way you are using Excel). Looking at the most detailed example in Murray's book (pp106-112) I think I'm right in saying he's using the starting lineup to base his offensive calculations on? That being so, am I also right in thinking that starting line ups aren't available until an hour or so before a game starts (yes, I really am a novice!)? Are you using your best judgment to "guess" the starting lineup the day before to do your calculations, or using some other method? I've been trying to simply use average runs scored by game (for either left or right handed pitching as appropriate) since Murray mentions that these numbers can work in many instances (p108) but I'm not sure how wise this approach is.

I hope the above (asking for further details of your methodology) isn't a breach of etiquette, if so please accept my apologies.

Cheers,

Mac

[TomG]

Updated YTD:
21.51 units wagered
+2.34 units
+10.9% ROI

Monday baseball has lots of experienced pitching which makes it easy to handicap based on stats. So I guess I *should* be pleased to see that nearly all of the posted lines are within 5% of my calculated "true lines." Only one pick...

Monday MLB
Oakland at Chicago
Oakland +114
Risk 1 unit to win 1.14

[ncboiler]

A couple stupid questions if you don't mind. I also came up with a spreadsheet that closely resembles what you have. I have correction factors for the bullpens, starting pitchers, and each teams offense. You talk about offensive power ratings and pitching power ratings. What are these? Also. Where do you get your stats?

Thanks in advance.

[TomG]

[ QUOTE ]
Tom,

I appreciate this question is slightly redundant given your comments about working on an improved model but could I ask for some clarification on the exact method you've been using to date to generate the offensive power ratings?

Let me be upfront and say I'm a relative newcomer to both baseball and baseball betting but I picked up Michael Murray's book a few weeks ago and have just got round to trying to put his method into practice (in much the same way you are using Excel). Looking at the most detailed example in Murray's book (pp106-112) I think I'm right in saying he's using the starting lineup to base his offensive calculations on? That being so, am I also right in thinking that starting line ups aren't available until an hour or so before a game starts (yes, I really am a novice!)? Are you using your best judgment to "guess" the starting lineup the day before to do your calculations, or using some other method? I've been trying to simply use average runs scored by game (for either left or right handed pitching as appropriate) since Murray mentions that these numbers can work in many instances (p108) but I'm not sure how wise this approach is.

I hope the above (asking for further details of your methodology) isn't a breach of etiquette, if so please accept my apologies.

Cheers,

Mac

[/ QUOTE ]
As far as I know, it isn't possible to get reliable batting order information prior to a few hours before the first pitch. So that leaves three options...

1) Use the teams "standard" batting order. This gives a reliable indicator of average offensive power but it doesn't account for substitutions or injuries.

2) Use the previous day's batting order. This will handle injuries but it won't handle regular rotations.

3) Wait for a few hours to prior to game time. This would be the most precise measure.

However, unless there is some batting order lineup that I don't know about, sports books aren't waiting for a few hours prior to game time before posting their lines. So I guess they just track injuries and then use a standardized batting order. When I post overnight picks, this what I am doing. I personally pull the standard line-up on top from here http://sports.espn.go.com/mlb/teams/lineup?team=bos. Then if it turns into a play I'll rundown the line-up to make sure the difference in value isn't likely the result of a line-up change.

I think using average runs scored is an okay methodology. I believe the main reason Murray recommends creating a power rating use SLG% and OB% is because it makes it easy to account for changes in lineup. You can't do this if you are just using a team's average runs scored. But I guess if you aren't accounting for changes in lineup anyway then a team's average team runs scored is an okay offensive power rating.

Good luck tinkering with things. If you run into any problems or have any ideas send me a PM or post a comment. I really do enjoy tweaking with this thing.