This might be a bit off topic, but I'l offer it up. I think the best trades are definitely quantifiable to a large degree even if we can't put an exact number to it.
As an example almost every stock out there has a stock that it correlates to, too some extent. The more stocks that you are familure with the greater edge you will have intraday because some always lead others.
For example if NOK suddendly rips higher because of some presentation or an intraday upgrade, etc, etc you might not be able to grab it fast enough, but knowing that say RFMD gets 40% of their revenues from them gives you an edge, IF NOK just bumped up 6% on expectations of increased orders and you know that rfmd supplies the rf chips for the phones and hasn't moved much then start hitting offers IMO.
i.e. you can often go buy the related stock which should move in sympathy as soon as everyone else figures it out. Often this lag is substantial (meaning several seconds... ;-)
A few weeks ago, someone downgraded sebl minutes before the open. It immediately dropped a buck but the naz futures were still up 9. I quickly started flipping through the software stocks...sure enough someone had left bids out on island for merq up 20 cents from the prev days close. (right in line with the where the futures were).
Obviously the sebl downgrade which everyone saw on the DJ newswire had not been fully dissemnated yet. I hit the bid and sure enough within a minute there were offers 70 cents lower than the bids I had just hit.
So from the above standpoint, I think you can find trades almost everyday that are definitely not random.
However as a caveat, it helps greatly to trade from an office or have access to some analytics (sp?) to help you spot these trades which are occuring every day only most of the time we many not see them because our knowledge base is too small.
When you are trading on a floor with 15-20 guys around you that know what they are doing. All day long your are getting information flow.
Things like, "Goldman has been holding the offer for the last 10 minutes if he lifts here this thing is going.....hey he just lifted"....or some guy yelling. Watch the banks, they are crushing BAC here", or the guy across the room yelling over, hey that spread I have been trading for the last three months, it just got really wide because there is a huge buyer in "xyz" but "abc" hasn't moved yet. You might want to buy abc here, it probably plays catch up.
I cannot tell you how much money that type of information flow made me.
The other thing which really helps me atleast quantify things on some level is if you can use stoplimit orders. Because then you can get two things going in your favor. For example the other day atvi had some good news and the other software stocks didn't move much in sympathy and even though they all make games for the x box, play station, etc, I didn't know for sure if atvi's good news would move erts and ttwo. On the open the two didn't move up much.
But atvi continued to move up and thinking that TTWO might follow later that day if you put in a buystop above the current price it meant that the stocks moved obviously seemed to be confirming your thesis.
In the above case the stock ripped pretty hard.
It certainly could have been random....but futures were sliding lower when it took off, TTWO had pretty much been in a 25 cent range before it bolted a dollar.
So for me atleast it was not random. I couldn't assign a probablity to it lifting, but I would feel confident that it was greater than 50%.
Cheers.
Oh and it may not be quantifable either but I have noticted that when that guy on the squawk box says that a paper just walked into the pit and is trying to buy 100 contracts and you know it's been locals only for the last few minutes and we have been drifting down. Buy just about anything you can, cause you are non-randomly about to rip like hell.
