Here's a great article by Dick Jerardi at the Daily Racing Form about Andy Beyer's speed figures, the ones I've been using for my very basic, beginner's-level handicapping.
Dick Jerardi: Beyer Figures not always based just on final time
Making Beyer Speed Figures is an art/science based on mathematics.
That was never more obvious than last Saturday at Fair Grounds when
Randy Moss, one of the original fig makers on the Beyer team, was
confronted with data that was, at first glance, confusing.
The Mineshaft Handicap, Rachel Alexandra Stakes, and Risen Star were
all run at 1 1/16 miles. Exactly 64 minutes separated the off times from
the first of those races to the third. Once Randy looked at the entire
card, it was clear that the variant was -12 Beyer points or 1.3 seconds
at the distance. That means to assess the performance of each horse, 1.3
seconds or 12 points had to be subtracted from the times/raw figures of
each race to account for the relative speed of the surface on the day.
The Rachel Alexandra’s time of 1:45.38 equated to a raw figure of 98. Thus, the actual Beyer assigned to the race is 86.
The Risen Star went in 1:44.52, a raw figure of 107. The Beyer is 95.
The Mineshaft’s time was 1:44.82, a raw figure of 104. The assigned figure is 97.
So, how does the slower race at the same distance on the same track
run an hour apart get a better Beyer?That is where art, common sense,
and pace are factored into the math.
(Read the rest of the article here ).
Still SO much to learn!!!