What do the different thumb dimples do for me?

​ We call these thumb contours Excelerators™ in our patented D.R.A.F.T.™ golf discs. Each pattern of Excelerators™ in the golf disc flight plate can be used advantageously for Ergonomics and/or Aerodynamics:

Ergonomically, the various Excelerator™ positions are designed to accommodate individual player preference, providing consistency and incremental adjustment as you dial in a comfortable and appropriate grip. You may experience the ability to put more spin and/or velocity on the disc, as the contours provide a lateral-dimensionally enhanced grip. Placing your thumb closer to the center of the disc seems to suit hyzer throws, as this may allow the nose of the disc to rise during launch. The thumb location on top is leveraged at-or-behind fingers below to lift nose. Placing your thumb farther to the outside (near the edge of the rim seems to suit anhyzer throws, as this tends to push the nose down. The thumb location on top is leveraged in front of the fingers below to push the nose down.

Aerodynamically, the Excelerator™ contours combine rotationally in flight to create a speed sensitive spoiler.. so discs traveling with more speed and spin experience turnover resistance (disc holds the line you put it on, with less hi-speed understability). Slower flying/spinning discs are minimally effected by turbulence from the partially-combined vacant space, which allows the disc's natural glide characteristics to prevail (disc holds the line you put it on, with less low-speed overstability).

US Patent #7,081,032

ABSTRACT
A flying disc for use in recreational activities and sports, such as for catch and throw, Ultimate, disc golf, and the like. The flying disc is configured for enhanced flight characteristics, throwability, trick shot capability and durability. The flying disc includes a circular flight deck section and an outer rim connected thereto. Contoured features are provided in a pattern in the flight deck section. The contoured features define cavities in the flight deck section and protrude beneath the flight deck section. The contoured features provide a variety of gripping positions on the top and bottom of the disc for generating greater snapping force when releasing the disc. The contoured features also create a Coanda effect that stabilizes the disc during flight. And, since the contoured features are recessed from the top of the flight deck section, the advantages of flight stability are achieved without a loss of flight distance.