Some basic stats

Jan1 - Jan23:

261 rated races won by:

The top rated horse: 91 (35%)
Top 2 rated horses: 141 (54%)
Top 3 rated horses: 176 (67%)
Top 4 rated horses: 203 (78%)

All horses rated at 30 or higher: 76 (29%) - from 225 runners (34%)
All horses rated at 15 or higher: 172 (66%) - from 703 runners (24%)
All horses rated at 10 or higher: 203 (78%) - from 1132 runners (18%)
All horses rated above the line: 230 (88%) - from 1454 runners (16%)

I've looked at the win returns using Unitab divs, and backing each top rated runner resulted in a tiny profit of 2%. From there, it got worse. The 2nd top raters made a loss of 12%, the 3rd top raters 18% and the 4th top raters 16%.

The winning strike rates are okay though with the top rater winning 35% of the time. In horse racing, that's not too bad. Also the top 2 win 54% of the time, the top 3 67% and the top 4 78%. Those are pretty good strike rates for people thinking about trifectas, first4s, doubles, trebles, quadrellas etc.