Brigadier Gerard won 2 key events viz. 2000 Guineas, King & Queen Diamond Stakes.
On the basis of Quality test...Mill Reef certainly was more glorious.
But compare their career runs the Quantitative index swings the other way :
MR was 14 starts with 12 wins (6 G1) & 2 2nd...pound 1/4 Million
BG was 18 starts with 17 wins (7 or 8 G1) & 1 2nd..US$ 3/4 Million
The 2000 guineas in 1971 was a 6 runner field..I believe BG beat MR by 1&1/4 length.
I would tie them both.
Both MR & BG were highly productive sires...MR's are better on track (Ibn Bey, Reference Point).
