Sveshnikov or Chelyabinsk?

While browsing Part 3 of Kasparov's 'Great Predecessors', which is the volume on Petrosian and Spassky, I noticed that Kasparov called the moves 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5 9.Bxf6 gxf6 10.Nd5, the Chelyabinsk Variation (p.54). I had always thought that the opening was a line in the Sveshnikov Variation and decided to check further.

Google counted 30-35K pages for each of the two phrases, with 12K pages for all three key words 'Sveshnikov', 'Chelyabinsk', and 'Variation'. Looking at the first few results for each phrase, I discovered that there is no consistency on the naming. The divegence starts early. A Chessville.com page said, 'The Sveshnikov Variation refers to 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5. This move order can also refer to the Lasker, the Pelikan, or Pilnik.' Although I was familiar with the other names, Pilnik Variation was new.

A JeremySilman.com page called the move 5...e5 the Sveshnikov-Pelikan and said, '9.Nd5 Be7; An interesting alternative for Black here is Timoshchenko’s 9...Qa5+. This whole variation we are looking at is mostly known as the Chelyabinsk variation, because it was mainly developed by two strong Masters from that city, Sveshnikov and the same Timoshchenko.' This is at odds with Kasparov's 9.Bxf6. Perhaps the author was referring to 8...b5 when he mentioned the 'whole variation we are looking at'.

There are many other online examples which I won't repeat here. The 'Oxford Companion to Chess' (p.468) calls 5...e5 the Pelikan Variation, 8...b5 the Chelyabinsk Variation, and 9.Bxf6 gxf6 10.Nd5 f5 the Sveshnikov Variation. About the only name on which everyone agrees is 8...Be6, the Bird Variation. Calling 10...f5 the 'Sveshnikov Variation' is at odds with all other authorities.

Who is the definitive authority on opening names?