Solution to Dear Johns

Frequently the flavortext contains information about the answer. Often this just serves as a nice confirmation once you find the answer, but sometimes it can be a shortcut to the answer. In this case, if you do a web search for bobsledder, designer, footballer and primatologist, you'll get the disambuation page for John Napier. A reasonable guess, given that the title is "Dear Johns", is then NAPIERS, which is the answer.

In the letter there are 7 sentences, each of which contains the word John. As clued by the flavortext "count on where he was" find the word position where John appears. This gives 14-1-16-10-5-18-19 and taking those letters of the alphabet spells NAPIERS.