A damned big clue, but pointing at what? When in doubt, get some numbers.

The biggest killer of deals is time, so speed is important. You should take your time to find the right deal for you, but once you've found it, you want to move.

From very early on, whenever I took a position in the markets, I wrote down the criteria I used to make my decision. Then, when I closed out a trade, I could reflect on how well these criteria had worked. It occurred to me that if I wrote those criteria into formulas (now more fashionably called algorithms) and then ran historical data through them, I could test how well my rules would have worked in the past. Here’s how it worked in practice: I would start out with my intuitions as I always did, but I would express them logically, as decision-making criteria, and capture them in a systematic way, creating a mental map of what I would do in each particular situation. Then I would run historical data through the systems to see how my decision would have performed in the past and, depending upon the results, modify the decision rules appropriately.

The key is having more information than the other guy – then analysing it right and using it rationally.

• Finding a good deal, the right business, the right people, the right investors, or whatever is just like dating. You must go to the market and talk to a lot of people, make a lot of offers, counteroffers, negotiate, reject, and accept.

to frame the decision, asking questions about the data and the methodology, working to understand the results, and using them to improve outcomes for your organization.

It's a difficult deal, a deal for which only time will show if it is economically viable.

You know, when you put out policy, like a 14-point plan? A lot of times in the first hour of negotiation, that 14-point plan goes astray, but you may end up with a better deal. That's the way it works. That's the way really life works. When I do a deal, I don't say, "Oh, here's 14 points." I got out and do it. I don't sit down and talk about 14 points.

I started negotiating the deal, which was complex beyond belief. I was creating structures and terms that had never been done before. I went to Jay and took him step-by-step through this incredibly complicated transaction. And damn it if he didn’t just look at me and say, “But, Sam, isn’t the real key to this whole thing just to rent the office space?” And sure enough, that’s what the whole transaction was predicated on. Jay’s level of intellectual rigor really appealed to me. And I immediately latched on to the understanding that I could cut right to the heart of something complex if I broke the problem into pieces. It was a matter of organizing my thinking. A discipline.

One of the most important things in this 'guess — compute consequences — compare with experiment' business is to know when you are right. It is possible to know when you are right way ahead of checking all the consequences. You can recognize truth by its beauty and simplicity. It is always easy when you have made a guess, and done two or three little calculations to make sure that it is not obviously wrong, to know that it is right. When you get it right, it is obvious that it is right — at least if you have any experience — because usually what happens is that more comes out than goes in. Your guess is, in fact, that something is very simple. If you cannot see immediately that it is wrong, and it is simpler than it was before, then it is right. The inexperienced, the crackpots, and people like that, make guesses that are simple, but you can immediately see that they are wrong, so that does not count. Others, the inexperienced students, make guesses that are very complicated, and it sort of looks as if it is all right, but I know it is not true because the truth always turns out to be simpler than you thought.

"How can we tell whether the rules which we "guess" at are really right if we cannot analyze the game very well? There are, roughly speaking, three ways.

First, there may be situations where nature has arranged, or we arrange nature, to be simple and to have so few parts that we can predict exactly what will happen, and thus we can check how our rules work. (In one corner of the board there may be only a few chess pieces at work, and that we can figure out exactly.)

A second good way to check rules is in terms of less specific rules derived from them. For example, the rule on the move of a bishop on a chessboard is that it moves only on the diagonal. One can deduce, no matter how many moves may be made, that a certain bishop will always be on a red square. So, without being able to follow the details, we can always check our idea about the bishop's motion by finding out whether it is always on a red square. Of course it will be, for a long time, until all of a sudden we find that it is on a black square (what happened of course, is that in the meantime it was captured, another pawn crossed for queening, and it turned into a bishop on a black square). That is the way it is in physics. For a long time we will have a rule that works excellently in an over-all way, even when we cannot follow the details, and then some time we may discover a new rule. From the point of view of basic physics, the most interesting phenomena are of course in the new places, the places where the rules do not work — not the places where they do work! That is the way in which we discover new rules.

The third way to tell whether our ideas are right is relatively crude but prob-ably the most powerful of them all. That is, by rough approximation. While we may not be able to tell why Alekhine moves this particular piece, perhaps we can roughly understand that he is gathering his pieces around the king to protect it, more or less, since that is the sensible thing to do in the circumstances. In t

You've got to balance the compassionate-use aspect with trying to figure out whether it works.

In modern times sound policy-making must often come to grips with numbers.

Wouldn’t it be worth working out what the actual criteria are?