Searching for Fritz

How can I follow-up my post on the Origin of 'Chess Engine'? Using the techniques described in Early Chess Newsgroups, I looked for early mentions of a name that has been nearly synonymous with 'chess engine' for more than 20 years: Fritz. My searches were hampered by a chronic problem producing the message, 'There was an error performing the search. Please try again later', so something might be missing. Here's a sample of what I learned:-

• 1991-06-28: Games of the 1991 AEGON Tournament • 'E. Blokhuis - Fritz...'
• 1991-07-19: Commercial Chess Programs • 'Fritz. Yet to be released ChessBase compatible program.'
• 1992-03-15: Software Reviews • 'Knightstalker: the German version of this program is called "Fritz"'
• 1992-09-30: ChessBase vs. NICBase • 'Fritz is a chess playing program the engine of which can be used within Chessbase so that at a particular time you can get an analysis of a game you are looking at in the database'
• 1992-11-30: 7th World Computer Chess Championship / Crosstable • '5 Fritz 2 | Netherlands / Germany | 11w= 8w= 15b+ 9b+ 2w= * 3.5 *'
• 1992-12-09: Chess computer game... which one? • 'Knightstalker 2 seems to be pretty improved. Also, news has it that Richard Lang is releasing his own PC program - it seems that his employer (Hegener & Glaser, Munich) for whom he wrote the MEPHISTO programs does a fast decline since they bought Fildelity [sic] America and lost a lot of money [...] I think it's now called Fritz II'
• 1992-12-27: Softwares & Ratings! • 'Fritz II and Zarkov 2.6 are strong chess programs that you're unlikely to find in computer stores. [...] I supplemented my Mac with a PC is for MChess (Pro), RexChess, Zarkov, and Fritz (II)'
• 1993-01-09: Chess Computer Ratings • 'Someone has asked for a list of chess computer ratings. [...] 28. Fritz AT 80486 (PC) 2.158'
• 1993-01-21: pc chess programs • 'Anand reached only 70 percent against Fritz 2 on 486, recently.'
• 1993-02-11: chess program speed • 'Fritz (=Knightstalker) [...] Fritz2 (successor of Fritz)'
• 1993-02-15: Some chess program news • 'an informal blitz match between GM Kasparov and Fritz 2 (i486/33 4MB) ended 26:11 (+24 =4 -9) [...] newest ratings for some PC programs from the Swedish list'
• 1993-05-05: AEGON TOURNAMENT • 'A huge number of top micros are entered, including 2 versions of Zarkov, 4 versions of the Chess Machine, Fritz II, Mephisto, MChess Pro, 3 different Saiteks, Socrates II, Chess Genius, Mephisto RISC, and many others.'
• 1993-05-10: COMPUTERS ELO LIST • 'I post this list in accordance to the various requests of a bigger list. [...] 22 Fritz 2 486dx 50 8 8 22.1 2240; 23 Fritz 2 486dx 33 4 4 15.2 2200'
• 1993-05-13: Aegon computer-human tournament result • 'These are the results of the 8th anual aegon computer chess tournament held in Voorburg (The Hague) The Netherlands.'
• 1993-09-13: FritzII strength? Comments? • 'KightStalker [sic] is the US version of Fritz, the predecessor of FritzII.'
• 1994-05-22: Kasparov (funny game, played in german television) • 'Kasparov was guest in german television (ZDF Sportstudio) and played the following game against Fritz3 running on a pentium'
• 1994-05-30: Fritz3's performance looks a little less impressive • 'PCA Munich Blitz Tournament: I am absolutely astonished to learn tonight that the players played Fritz3 in this tournament at a computer terminal.'; M.D.Crowther

The entries for 1993-02-15 and 1994-05-22 indicate that Kasparov was routinely hired to promote important milestones in the evolution of Fritz. Using my page Garry Kasparov's Tournament, Match, and Exhibition Record (1973-) as a reference, here's what I found:-
1992-12 Match vs. Fritz 2, Cologne • +26-11=3 (?)
1994-05 Intel Express Challenge (Blitz), Munich • 1-2/18, +12-4=1
1994-05 Intel Express Challenge (Blitz) - Playoff vs. Fritz, Munich • +3-0=2
1995-12 Match vs. Fritz4, London • +1-0=1
1999-03 Simul and Rapidplay (15') vs. Fritz, CeBit, Hannover • S:? F:+0-0=2
2003-11 X3D Match w/ Fritz, New York USA • +1-1=2

From this I would guess that Fritz4 was released end-1995, a conjecture I'll leave for another time. Other keywords for further research: Aegon, ChessBase (& other databases), World Computer Championship, Computer Ratings.