There are a couple of erroneous points to dunno's post, which I'll attempt to address individually:
1. The terms Center of Gravity (CG) and Center of Mass (CM) are synonymous in uniform gravitational fields. The gymnast and High Bar has CM just the same as any other object. The distinction here is unnecessary.
2. The point of release of the CM in a Kovacs is approximately 43° to neutral bar angle (Kerwin et al 2007) for a tucked Kovacs. In order from gymnast to be able to re-grasp (and avoid several other implausible outcomes that were clearly not considered), the gymnast would need to rotate a minimum of 403°. However, to preserve the kinetic energy accrued from the somersault going in to the subsequent skill, this has got to be closer to 500° - at an absolute minimum.
3. There have been several attempts by biomechanists to change the wording of Kovacs in the CdP so that it falls in line with the description of Gaylord I, so far to no avail.
4. Dunno, should you wish to engage in a discussion about the movement properties of gymnastics skills for any reason other than your own ego, I would be more than happy to do so. However, I would recommend spending some time doing some further reading on biomechanics before doing so.
5. The Tkatchev is not a salto. However there's an interesting paper from Ivan Cuk detailing the biomechanical properties for the (yet to be performed in major competition) Tkatchev-salto which might be of interest: Link Removed