On the CCRL (Computer Chess Rating Lists) it's ranked number 7 at 3172 which is a considerable distance behind Komodo 9.42 (3354), Stockfish 7 (3337) and Houdini 4 (3255).
On the CEGT (Chess Engines Grand Tournament) rating list Fritz 15 is ranked in 6th place at 2965, also way behind Komodo 9.3 (3244), Stockfish (3243) and Houdini 4.0 (3066).
On Owl Computer Chess Engines Fritz 15th is in 9th place. The top three are Stockfish (3441), Komodo 9.42 (3416) and Houdini 4 Pro (3345).
The IPON-Round Robin Rating List also has Komodo 9.42 (3236), Stockfish 7 (3232) and Houdini 4 (3123) as the top rated engines with Fritz 15 in 7th place (3001).
So, it appears that Fritz 15's results have been disappointing. That's not to say that it hasn't improved because on the CCLR 40/40 rating list for all engines (all versions) Fritz 15 is in 7th place at 3172 while Fritz 14 is way down in 28th place at 3024.
Komodo 9.4 sells for $60 and the one year subscription for free upgrades is $100. By the way, you can download Komodo 7 for free on the site HERE. Version 7 is still pretty good. On the CCLR list for all engines, all versions it's tied for 6th place at 3181. You might want to download it for use along with Stockfish because Komodo is probably the most positionally accurate in middlegame positions with no tactics and it's also good in the openings. But, it needs longer analysis time than Stockfish.
Of the other strong free engines ChessLogik's open-source development of Fire has officially ended and is no longer available for download, but the open source Gull engine (3199) is available at SourceForge. Another good engine is Critter which can be downloaded HERE.
Given that Komodo is in a nip and tuck battle for first place with the free Stockfish, both of which are far ahead of their competitors, I don't see any reason to part with $63 just to get the Fritz 15 engine that comes with the GUI. That is unless you want the Fritz GUI which is, in my opinion, one of the best available. But, personally what I would do is buy Fritz 13 (the download version is $40 and only available to customers located in the United States) or even Fritz 12 if you can find it, then add Stockfish to the engine list. I've used Fritz 12 for years and found it perfectly satisfactory because I'm not interested in all of the training features and access to online engine analysis features that later versions offer.
I also use Chess Assistant 16 which also has some great features not available in Fritz 12, but it's interface is not as clean and it takes time to learn to use all its features.
|Chess Assistant 16|