The old saying had it "All roads lead to Rome." Looking at the performance of the modern gamecock I think the same thing can be said about Boston RH.
Starting with the most recent WSC 2003. Wasn't the he guy who won it (or co-shared the title) just started to get into cockfighting, and his birds were a cross between Boston RH and another strain?
Roger Robert's Hatchets won it in 2001 (also first appearance) and they were crosses between either Hatch & RH, or Chet & RH. Judging by their appearance (light red/orange, yellow legged), they certainly look like Boston RH.
Both the modern day YL Hatch & Sweater have been said to have Boston RH influence, some may even say heavy influence. Again, judging by their appearance and performance (we know pure Hatch doesn't really cut that well), it's not too far off. These are the birds that put Carol N., Bruce B., Nene A., Sonny L.... in the the "who-is-who" of the cocking world.
The most famous RH of them all: the Allen RH, which had the best winning record in the southern states, and which is the foundation of almost all modern RH, was a cross between a Boston RH cock and 5 Grist Grady hens, breeding to the RH side until 7/8 or 15/16 RH. Colonel Allen described his Boston RH brood cock as "... yellow leg, peacomb, light red, w/ white streamers in the wings and tail..." Doesn't that sound just like the modern day Sweater?
Which brings me to an old superstitious theory from Vietnam. Red is above white (gray), meaning when a red go up against a gray it will win MOST of the time; light red is above dark red; and whitetail (some streamers, not whole) is above blacktail. So perhaps the old guys' theory has some validity... And you just need to get some Boston RH blood in your yard if you haven't got it.