If Marcy was insulted, he wasn't daunted. The promise of finding a planet had all the gee-whiz factor a scientist could ask for, enough to keep him on task for 12 years without a payout. And the work was hard. He had to make his astronomical instruments 1,000 times more sensitive than those his colleagues were using. Think back to Marvin the alien on his planet 30 light-years away.
Gravity connects Jupiter to the sun.
But Jupiter has a gravitational pull, too, and it exerts a force on the sun. The sun doesn't move much, but it does lean slightly toward Jupiter as the planet revolves. Our alien astronomer 30 light-years away cannot see the planet, but maybe he can see the sun move a bit. That's exactly what Marcy has done. He developed a technique to catch stars leaning toward their planets as the planets revolve.