Chess Engine 'Styles'

I don't think I can trust the programmer's descriptions of the styles of these programs because they all say they're tactically brilliant, deep, creative, agressive, and accurate. I'm not so much interested in which is best, but more interested in their 'style' though I appreciate that to a large extent they're 'machine-like'(!)

How would you describe the playing styles of any of these engines: Fritz 14, Rybka 4, Hiarcs 14, Junior 14, Shredder 12, Stockfish 5, Komodo 8, and Houdini 4?

They all have a thump-a** style from my perspective.

But seriously, lots of people say that Junior has a very sacrificial style.

Do you know whether older versions or newer versions of Junior are more likely to go for sacrificies? And do you know how speculative the sacrifices are?

If they all play the best moves, how can they play differently? Wouldn't the computer ratings charts just list all the programs with the same elo if they all played the same?

I don't think you know what you mean.

And obviously they don't look at every combination.

I appreciate that I'm using the word 'style' in an unusual way, hence the quotation marks, but I'm interested in those differences you refer to in the way one engine evaluates one move as compared with another. Which engines evaluate more aggressive moves more favourably, which engines evaluate sacrifices more favourably, which engines evaluate safer and more solid moves more favourably etc.

The most striking thing about any engine play is it can't take into account any deep plan, and anything outside its search horizon doesn't exist.

So you get very reasonable moves, unreasonable but tactically justified moves, and unreasonable unjustified moves. I suppose the style could be called inhuman.

Sometimes I suspect I know what they're misevaluating though. In particular I sometimes see stockfish suggesting space gaining moves that aren't good.