Supposedly, you're supposed to minus 15 from the Racing Post to get a Beyer. For example Strike the Deal has a very strong 112, which equates to around a 97 Beyer.
Steve
Timeform ratings are handicap figs - as in handicap weights - meaning the fig you see for that horse's race is the weight that should be imposted on that horse if that same field were to race again at that track, over that surface and at that distance. Because we are dealing with a limited range of numbers when talking about BSFs and Timeforms, it's only coincidence that by deducting some fig from the Timeform that it matches or comes close to the BSF the horse would have earned had it been given a BSF.
Additionally - Timeforms are age based. A 3 year old who earns a 120 Timeform is inferior to a 4 year old who earns a 120 Timeform.
I hope this helps.
The Bobtail
If you don't want the genie to pop up - don't rub the lamp.