Yes, I understand that, but I still want to know: is it worth the extra $30?
Friz 13 or Deep Fritz 13?

I guess it depends on how you will use it, and if your computer is able to make use of the program correctly. Deep Fritz allows your computer's multiple processors to compute separate lines simultaneously. If you have a quad core, it can compute lines 4 at a time. My PC is a dual core, so it isn't nearly as beneficial to me as it would be to you if you have a quad core. I don't have either, but have wanted Fritz 13 for a long time. I've waffled on buying it, but Arena is free, and comes with Rybka 2.2 and several other engines all totally free. The GUI is quite easy to understand, and free. Did I mention that it's free? Lol, I'm sure Deep Fritz would be awesome, though. If I had plenty of extra cash, I'd buy it.

I know Deep you have to pay for the deep part after 6 months and both adjust to your level of play but why did they put out two versions? Can anyone explain why they are both Fritz but one is put out ChessBase and the other by Viva Media?
I'd just like to start out with a computer "teacher" before I embarrass myself on chess.com playing live.
I already have Fritz 13 but I am thinking of upgrading it to Deep Fritz 13, to take advantage of my new i7 quad-core processor. Does anyone know how you install Deep Fritz 13 over Fritz 13? Do you have to uninstall Fritz 13? Are there any problems in upgrading from Fritz 13 to Deep Fritz 13.

Stockfish is more powerful and completely free and open source.
That's right. You need Fritz not for the chess engine (which, although good, it's far from being among the best), but for its functionality. You'd be better off installing and using Stockfish, Critter and Houdini 1.5 for you analysis in Fritz, and that's what I'm actually doing. Note that Critter is better in analysing tactical positions and Stockfish is better at more strategic situations.
BTW, starting from Fritz 14, it comes only in the Deep version (since single core processors is a thing of the past).

I have Fritz11 for its GUI, but Arena is useable too and is free (although imo harder to use).
However, note Stockfish have give optimistic evaluations.

I can let anyone know about Deep Fritz 14, it's on it's way. Just ordered it on Black Friday (20%) off so I haven't tried it yet. Keep my link and ask me in a week or two and I'll do my best to update. I have never owned a chess program before so I'll have a long learning curve. BryPin
Fritz is like the Adobe Reader: Needs updates every now and then, but it is always the same software.

Arena is free as in beer but proprietary and SCID vs PC is free and open source.
When I used Arena I did find it a bit awkward to accomplish things, but I figured everything out pretty quickly. SCID, on the other hand, is extremely easy to use. Personally I've been using ChessX recently which I think is just yet another fork of SCID.
These programs are just as capable so it baffles me why people would spend so much money on software.
Hi.
I was looking for a chess engine to start analyzing my tournament games, and now I'm torn between Regular Fritz and deep fritz:
Normal Fritz costs around $40
Deep Fritz costs around $80 but is apparently a stronger engine and thinks around 60% faster.
So, i suppose my question is: Is Deep Fritz worth the extra $30-40?