what do the fractions mean in some chess books?

I'm reading this Tal-Botvinnik 1960, and there's a number after each move, like 16...Nd7-e5(0.39). Anyone knows what's this number 0.39? time? 0.39 second? Kind of confusing...

Probably computer evaluations

http://support.chess.com/Knowledgebase/Article/View/120/6/what-do-the-computer-evaluation-numbers-mean-like-225

Or not then...

Thank you, Es. I think you are right.

Sorry Scot, it's Tal who wrote the book. I don't suppose he was able to use a laptop...

I'm glad I stumbled on this topic.  I have the book, but when I opened it I noticed what looked like computer evaluations throughout and I was so disgusted that I never opened it again.  I have it here in front of me now and I see that the time explanation makes sense.

Thanks so much, I'm now free to read this book

3 weeks is a bit late to answer about your own question don't you think?

The truth will set you free!

So what's that to you?

It couldn't be computer evaluation for sure... But why would computer evaluation be disgusting?

1) I bought it some time ago and didn't trust that the computer was stronger than two world champions... certainly not for all the moves (especially openings and endgames).

2) Even modern programs and fast hardware give poor evaluations sometimes so you have to use multiple programs and let them think a long time if you want to even attempt WC quality analysis.

3) Computers are completely unaware of pratical chances.  I.e. the best OTB move will not always yeild the best numerical score.  Sometimes "blunders" are very hard to refute and the "best" move offers no practical resistance.

For all these reasons I didn't want to read Tal saying "this move was good" and then see the idiot publisher say he is wrong by showing that the numerical evaluation goes down.  Especially considering one of the main selling points of the book to me is Tal was a writer and so you're sure to get a honest human perspective e.g. my last loss made me timid, I was short on time, I felt energetic and started inventing over the board, etc etc.

I actually bought some white out the next day intending to blank all the numbers out, but it was too tedious and I never did, so it just sat on my shelf all this time.

interesting view... I agree with you this book is superb in its honesty

These books were published long before computers were strong enough to be considered useful. Estragon and Wafflemaster are exactly right. The (.39) is 39 minutes.