Overlapping Cycles in the 1980s

While working on a post for my main blog, Kasparov TMER: Last updated 2014-05-19 [TMER: Tournament, Match, and Exhibition Record], I realized I had only a hazy recollection of the events surrounding the Kasparov - Karpov title matches played in the 1980s, especially the two overlapping cycles provoked by the termination of the 1984 match. My index page, World Chess Championship : FIDE Events 1948-1990, shows a nice, orderly progression of the two key cycles (C12 & C13), which is misleading.

Here are those same events presented in chronological order. The '}' in the last column shows events in the two cycles which were played at the same time.

	C12: 1982-1984	C13: 1985-1987
1984-09/ 1985-02	Karpov - Kasparov (I)
1985-04/-07		IZ Tunis IZ Taxco IZ Biel
1985-09/-11	Kasparov - Karpov (II)		}
1985-10/-11		CT Montpellier	}
1986-01/-02		CM QF Matches
1986-07/-10	Kasparov - Karpov (III)		}
1986-09/-10		CM Sokolov - Yusupov	}
1987-02/-03		CM Karpov - Sokolov
1987-10/-12		Kasparov - Karpov

While working on this last table I noted a few other points of interest, but ran out of time before I could investigate them further.