DAYS SINCE LAST START

[mountainman]

Have query for someone with a d-base. What are the avg, median, and most frequent number of days between starts for american t-breds? Please exclude laid up horses, if possible. Suggest cutoff point at 45 days. Need info for day job. Tx in advance.

[DeltaLover]

average days off: 43.0567870884
stdev : 63.9649372945

Sample size: 143,999

I will post later today a document the analytical break down... Right now I am at the track and cannot access my
ftp server
Please let me know if you need more info

[JustRalph]

My stuff is almost exactly the same as Delta Lover.

I also find that horses that start between 55 and 70 days are less likely to win, even if they are Favs

After 70 days it's basically "laid up" to me and the numbers go all over the place

[mountainman]

Tx guys, but i'm more looking for the avg interim for horses not rested for a significant period or potentially removed from training. So, could you possibly supply the avg number of days since last start for all horses running back in less than 45 days (an arbitrary time-frame in part selected to coincide with drf's "layup line") ??

This is not requested for handicapping purposes, but instead to be referenced in negotiations with horsemen concerning the rotating of races in our condition book.

[davew]

I would think you are asking a chicken - egg which came first type question.

The condition book rotation at a specific track would depend on length of track season, number of horses at track, type of horses at track, and whether big groups of horses enter/leave as other tracks open/close.

As long as you are negotiating with horsemen, why not ask them what they would like for number of days to return their horses for next race. I suspect as a bettor, many trainers would like the 10-14 day range, but surely would be individual horse dependant.

[mountainman]

Originally Posted by davew

The condition book rotation at a specific track would depend on length of track season, number of horses at track, type of horses at track, and whether big groups of horses enter/leave as other tracks open/close.

Indeed. Having served as a racing official for some 23 years, i can attest that you're, in large part, correct. But the chicken/ egg analogy doesn't really apply to the huge sample size i need for representative data.

And, believe me, if you poll 20 horsemen on how to write a condition book, you will get 20 different -and EXTREMELY self-serving answers. Each will want the book tailored to his stock and particular training methods.

In addition, the info i've requested won't be used in tooling the condition book, but in supporting our argument for the way it's currently written.

[Jeff P]

Originally Posted by mountainman

Tx guys, but i'm more looking for the avg interim for horses not rested for a significant period or potentially removed from training. So, could you possibly supply the avg number of days since last start for all horses running back in less than 45 days (an arbitrary time-frame in part selected to coincide with drf's "layup line") ??

This is not requested for handicapping purposes, but instead to be referenced in negotiations with horsemen concerning the rotating of races in our condition book.

Here's what I have in the database for all starters (thoroughbred only) from Jan 01, 2012 through yesterday Sat Nov 16, 2012 that a.) made a start within that date range and b.) whose most recent race back was within 45 days of the start recorded in the database. (I think that's what you are asking for.)

First, all starters in the database fitting that description:

query start:         11/18/2012 5:05:11 PM
query end:           11/18/2012 5:08:52 PM
elapsed time:        221 seconds

Data Window Settings:
Connected to: C:\JCapper\exe\JCapper2.mdb
999 Divisor  Odds Cap: None

SQL:  SELECT * FROM STARTERHISTORY
      WHERE RACEDAYS <= 45 
      AND [DATE] >= #01-01-2012#


Data Summary         Win      Place       Show
----------------------------------------------
Mutuel Totals  411880.00  415724.30  417524.60
Bet           -546000.00 -546000.00 -546000.00
Gain          -134120.00 -130275.70 -128475.40

Wins               36472      72951     106499
Plays             273000     273000     273000
PCT                .1336      .2672      .3901

ROI               0.7544     0.7614     0.7647
Avg Mut            11.29       5.70       3.92

Next, data for the above starters broken out by days last start:

By: Recent Activity- Days Last Start

>=Min     <= Max      Gain       Bet       Roi   Wins  Plays     Pct   Impact
-----------------------------------------------------------------------------
    1          4   -139.70    626.00    0.7768     51    313   .1629   1.2196
    5          9  -9982.40  38682.00    0.7419   2484  19341   .1284   0.9613
   10         14 -28912.60 112950.00    0.7440   7274  56475   .1288   0.9641
   15         19 -26839.10 104500.00    0.7432   6877  52250   .1316   0.9852
   20         24 -28604.70 112780.00    0.7464   7444  56390   .1320   0.9881
   25         29 -16940.80  75702.00    0.7762   5168  37851   .1365   1.0220
   30         34  -9005.20  39422.00    0.7716   2767  19711   .1404   1.0508
   35         39  -7921.60  32838.00    0.7588   2377  16419   .1448   1.0836
   40         44  -5223.80  26106.00    0.7999   1870  13053   .1433   1.0723
   45         45   -550.10   2394.00    0.7702    160   1197   .1337   1.0005

How to read...

There were exactly 273,000 starters in the sample who came back to race within 45 days of their most recent start.

Each row in the second section shows a min and max range for days last start... For example, the 3rd row in that section is for horses whose most recent start was between 10 and 14 days inclusive. There were 56,475 starters in that row (representing 20.69% of the total sample.)

Hope that helps.


-jp

.

[Jeff P]

Same query... MNR Only:

query start:         11/18/2012 5:36:15 PM
query end:           11/18/2012 5:36:30 PM
elapsed time:        15 seconds

Data Window Settings:
Connected to: C:\JCapper\exe\JCapper2.mdb
999 Divisor  Odds Cap: None

SQL:  SELECT * FROM STARTERHISTORY
      WHERE TRACK='MNR' 
      AND RACEDAYS <= 45 
      AND [DATE] >= #01-01-2012#


Data Summary         Win     Place      Show
--------------------------------------------
Mutuel Totals   17418.00  17617.00  18229.40
Bet            -22812.00 -22812.00 -22812.00
Gain            -5394.00  -5195.00  -4582.60

Wins                1549      3040      4345
Plays              11406     11406     11406
PCT                .1358     .2665     .3809

ROI               0.7635    0.7723    0.7991
Avg Mut            11.24      5.80      4.20

By: Recent Activity- Days Last Start

>=Min     <= Max      Gain       Bet       Roi   Wins  Plays     Pct   Impact
-----------------------------------------------------------------------------
    1          4     17.60     28.00    1.6286      6     14   .4286   3.1558
    5          0   -406.60   2120.00    0.8082    138   1060   .1302   0.9586
   10         14  -1090.00   4944.00    0.7795    354   2472   .1432   1.0545
   15         19  -1085.00   4780.00    0.7730    345   2390   .1444   1.0629
   20         24  -1089.60   5404.00    0.7984    355   2702   .1314   0.9674
   25         29   -704.00   2180.00    0.6771    133   1090   .1220   0.8985
   30         34   -491.80   1484.00    0.6686    103    742   .1388   1.0222
   35         39   -572.80   1034.00    0.4460     61    517   .1180   0.8688
   40         44     -1.80    756.00    0.9976     48    378   .1270   0.9350
   45         45     30.00     82.00    1.3659      6     41   .1463   1.0776

-jp

.

[Overlay]

Jeff's numbers indicate why I was having trouble understanding the statements by DeltaLover and JustRalph to the effect of their data showing that the average days off between starts for all horses was slightly over 43 days. According to Jeff's figures, the great bulk of starters in his sample (which I agree was limited to horses coming back within 45 days) came back within 30 days or less. I find it difficult to believe that there would be enough horses taking a layoff of over 45 days between starts to make the composite average for all horses work out to 43 days, especially with the way the number of horses starts dropping off dramatically in Jeff's sample once you get past 30 days. Or am I misinterpreting something about DeltaLover's and JustRalph's data/statements?

[Jeff P]

For the all starters coming back to race within 45 days sample above:

Sum of days last start all starters: 5,822,538
---Number of starters in the sample: 273,000
---Avg number of days since last race: 21.33




For the MNR only sample above:

Sum of days last start all starters: 226,089
--Number of starters in the sample: 11,406
-Avg number of days since last race: 19.82





-jp

.

[DeltaLover]

complete breakdown in csv format:

http://kasosoft.com/days_off_per_starter.csv

[Jeff P]

Originally Posted by Overlay

Jeff's numbers indicate why I was having trouble understanding the statements by DeltaLover and JustRalph to the effect of their data showing that the average days off between starts for all horses was slightly over 43 days. According to Jeff's figures, the great bulk of starters in his sample (which I agree was limited to horses coming back within 45 days) came back within 30 days or less. I find it difficult to believe that there would be enough horses taking a layoff of over 45 days between starts to make the composite average for all horses work out to 43 days, especially with the way the number of horses starts dropping off dramatically in Jeff's sample once you get past 30 days. Or am I misinterpreting something about DeltaLover's and JustRalph's data/statements?

Running all starters in the database that a.) raced between Jan 01, 2012 and Sat Nov 16, 2012 and b.) had at least 1 lifetime start... I get roughly the same as what Ralph and DeltaLover came up with:

Sum of days last start all starters: 14,031,112
---Number of starters in the sample: 331, 274
---Avg number of days since last race: 42.36

Apparently limiting the query to just those coming back within 45 days does make a difference.


-jp

.

[Jeff P]

Tim, Here's what that bigger sample looks like:

Data Window Settings:
Connected to: C:\JCapper\exe\JCapper2.mdb
999 Divisor  Odds Cap: None

SQL:  SELECT * FROM STARTERHISTORY
      WHERE STARTSLIFETIME > 0 
      AND [DATE] >= #01-01-2012#


Data Summary         Win      Place       Show
----------------------------------------------
Mutuel Totals  498420.80  502488.50  501650.20
Bet           -662548.00 -662548.00 -662548.00
Gain          -164127.20 -160059.50 -160897.80

Wins               43595      86765     126536
Plays             331274     331274     331274
PCT                .1316      .2619      .3820

ROI               0.7523     0.7584     0.7572
Avg Mut            11.43       5.79       3.96

By: Recent Activity- Days Last Start

>=Min     <= Max      Gain       Bet       Roi   Wins  Plays     Pct   Impact
-----------------------------------------------------------------------------
    1         14 -39034.70 152258.00    0.7436   9809  76129   .1288   0.9791
   15         29 -72384.60 292982.00    0.7529  19489 146491   .1330   1.0109
   30         44 -22150.60  98366.00    0.7748   7014  49183   .1426   1.0837
   45         59  -7791.40  35672.00    0.7816   2451  17836   .1374   1.0442
   60         74  -2930.30  16294.00    0.8202   1143   8147   .1403   1.0661
   75         89  -2356.90   9172.00    0.7430    573   4586   .1249   0.9494
   90        104  -1534.30   6106.00    0.7487    369   3053   .1209   0.9184
  105        119  -1456.60   4644.00    0.6863    256   2322   .1102   0.8378
  120        134   -856.30   3894.00    0.7801    206   1947   .1058   0.8040
  135        149   -753.40   3672.00    0.7948    217   1836   .1182   0.8981
  150        164  -1175.60   3422.00    0.6565    166   1711   .0970   0.7372
  165        179  -1174.20   3470.00    0.6616    173   1735   .0997   0.7577
  180        194  -1343.70   3666.00    0.6335    201   1833   .1097   0.8333
  195        209   -543.90   3306.00    0.8355    205   1653   .1240   0.9424
  210        224  -1114.30   3650.00    0.6947    193   1825   .1058   0.8036
  225        239  -1280.30   3324.00    0.6148    171   1662   .1029   0.7818
  240        254   -729.90   2708.00    0.7305    146   1354   .1078   0.8194
  255        269   -578.50   2490.00    0.7677    140   1245   .1124   0.8545
  270     999999  -4937.70  13452.00    0.6329    673   6726   .1001   0.7603

It's not that the larger sample differs materially from the smaller samples... it doesn't.

It's that none of the starters in the smaller sample have a days last race number greater than 45... while enough of the starters in the larger sample do. Once you start adding up the total number of days and dividing by the number of starters to get an avg... the avg days last race per starter does differ significantly in the two samples.

Hope I managed to get most of that out in a way that makes sense.


-jp

.

[Overlay]

Thank you, Jeff. The absolute number of long-layoff horses is not that great, but I hadn't been giving sufficient consideration to the fact that it only takes a relatively small number that have been off for hundreds of days to drive the mean layoff up for the entire population, even if the values for the median and the mode would be much lower, and possibly more representative of the population as a whole.

[traynor]

Originally Posted by Overlay

Thank you, Jeff. The absolute number of long-layoff horses is not that great, but I hadn't been giving sufficient consideration to the fact that it only takes a relatively small number that have been off for hundreds of days to drive the mean layoff up for the entire population, even if the values for the median and the mode would be much lower, and possibly more representative of the population as a whole.

The same thing happens with ROI figures with a few aberrant mutuels tossed into the mix.