I just reviewed that old thread about fireball smash probabilities and realized that no one ever completed the task of updating the probabilities based on the last wrinkle that was found in the code regarding fireball speeds on the various internal difficulty levels. It would be nice to know if this does or does not affect the numbers at all and whether it makes them "better" or "worse" than the 3:2:1 ratio that was first mentioned.
In general, I do believe that with that board setup (2nd rivet from the top on the right remains, all firefoxes are trapped on the top left side, Jumpman is taunting Kong on the right side), getting 3 smashes is pretty much exactly break even. This assumes that you leave exactly enough time for your hammer to expire before clearing the screen at the last possible moment. This is because the hammer lasts for exactly 9 Timer ticks on Level 4+ AND there is additional time wasted (inefficiency) by running from the bottom of the ladder to the middle of the screen where the hammer is -- somewhere in the range of 1 more Timer tick. At my taunting ratio of 10 jumps per 8 Timer ticks, we're talking about giving up about 12.5 - 13 jumps in order to grab the hammer under these exact conditions. That's 1300 points given up which is almost precisely what we're going to find is the expected value of 3 smashes. Furthermore, with the knowledge that the chances to smash the two freezers over there is extremely low, and the relatively common screwing of a non-freezer climbing the far ladder and also avoiding being smashed, I'm thinking more and more that the expected number of smashes in this setup is less than 3. (By the way, this opportunity cost is independent of the level -- the speed of the Timer does not matter since the hammer always lasts for the same amount of real time and you can always get the same amount of taunting points during that real time.)
I have a couple of ideas for creating slightly alternate situations -- let's hear your thoughts on these. First, who says you must time it so that you will end the screen exactly when the hammer expires? What if you intentionally grab the hammer "late" and use up only half of your hammer time (4 or 5 Timer ticks of hammer time)? Now you're only giving up 600 - 700 taunting points and you'll have just enough time to go to the left, get some smashes and then you'd need to almost immediately turn around and finish the stage. Your expected number of smashes with this strategy is obviously slightly less, but you might be able to time it so that even just TWO smashes is now profitable... Secondly, what if, while taunting, you quickly pause and drop a toe down the ladder and try to get the freezer to drop down and go into it's pattern of climbing down, pausing at the bottom of the ladder and then climbing back up and pausing again at the top of the ladder IF the fireball's position is higher than or equal to jumpman's position, you make sure that you are in the air when it climbs back up (do some more taunting) and then very shortly thereafter you are going down and going for the hammer. The idea is that the freezer has not had a chance to go back into its freeze mode pattern yet and can now be smashed. My gut tells me that this would not be a profitable move on average, but it might be worth thinking about.
In addition, even a slight modification on the overall scenario might make a difference. Suppose 4 fireballs are trapped on the top left, but you have 1 fireball trapped on the top right -- if the one on the right side is a freezer this could change things since it IS possible to reach across the gap and smash a freezer sitting at the bottom of the ladder on the right side, but not on the left side (very wierd, but true in my experience). This might increase the expected number of smashes to more than 3 for that scenario.
Lastly, I've been thinking more and more that grabbing a hammer IN GENERAL loses points if a significant amount of efficiency is lost in the process -- and the length of the delay is probably less than we'd think. This goes for all hammers on the rivet and conveyor screens. The obvious example is when you're using a star pattern on the rivet screen and you might be able to race up the right side to unplug the last two rivets and end the screen very quickly for a big Timer bonus, but in instead you stick with the star pattern, try to go up the middle ladder and are delayed by perhaps 10 - 15 Timer ticks before actually getting a chance to grab the hammer. Now, having this hammer in your hand is generally inefficient as well since you have to sit around and wait for it to expire before you can climb up for the last rivet -- perhaps another 3 or 4 Timer ticks lost. Now, we're talking about needing pretty massive numbers of smashes with the hammer to compensate for a relatively typical delay. On the other hand, in addition to the smashes, some percentage of the time (no where near 100%) you'll have an opportunity to taunt out the screen, which "adds" to your Timer bonus, sometimes 1000 points or more. So, how much delay makes the decision unprofitable is sort of unclear.
I've been pretty unhappy lately with my rivet averages and I think I might start looking more and more for situations where I can skip the hammer.