historic_races_beta missing races?

Question

Hi

I've been running some spot checks on my analysis and I noticed some discrepancies between daily_races_beta and historic_races_beta, for example:

select * from daily_runners_beta ru
inner join daily_races_beta ra on ra.race_id = ru.race_id
where name = 'Buckshaw Village' and meeting_date = '2022-09-08'

This returns 1 row, whereas this:

select * from historic_runners_beta ru
inner join historic_races_beta ra on ra.race_id = ru.race_id
where name = 'Buckshaw Village' and meeting_date = '2022-09-08'

returns no rows.

This kind of messes up my historical analysis as when running through previous dates, it uses the historic_races_beta as the race details for the date in question.  When I go back and simulate the picks for this date using daily_races_beta, it chooses more horses as there are more races.

Is this anomaly a frequent occurrence?

Thanks

Answer 1

There are no missing races from the database here, the issue is that you should  only use races for your historic analysis that have results associated with them, so discard any races or horses from the daily races that do not, if using the data for historic analysis.

Remember that daily races are compiled in advance (essentially racecards) before the races actually occur.  Any horse that is listed may subsequently be declared a non-runner, and any race may be subject to abandonment.  

This is the case with the example you have listed - the majority of the card at Southwell on that date was abandoned, including the race in which Buckshaw Village was due to compete.

See:

https://www.sportinglife.com/racing/results/2022-09-08

Comments

That makes sense.  As it happens, the historic analysis in this case is fine as it does ignore those races.  I do spot checks on my results by simulating a historic date but for that I use daily_races_beta (for the historic date) and because that had the race and runners, it gave more results.

Thanks for the prompt response, really appreciate it.