Geoff,
Should you use the core putt to calibrate the timing/speed of how fast/slow you say "one potato"?

Dear bgolfing,

No. Gravity never changes, so the count never changes. Find out what one specific backstroke plus the same tempo will result in for distance of roll on the green, and accept that as your core putt. This calibrates your internal tempo with the green speed of that specific green that day. The greens change, but the tempo never changes.

Cheers!

Geoff Mangum
Putting Theorist and Coach
PuttingZone.com