@Chilli_Dipperin r/trackandfield • Recommends
On “Pacemakers bridging the gap to competing ”
The simple answer is because that’s what they’ve been paid to do, and they are only prepared to run the prescribed distance and pace.
That said, it’s not completely unheard of for pacemakers to stay in the race. Tom Byers was entered as a rabbit in a 1500 race at the Bislett Games in 1981, and after none of the elite miles took to his pace, he kept going and finished first. The pacemaker of Galen Rupp’s 10,000-meter American record attempt in 2014 stayed in the race after his work was done, and set a PB while doing so.