I'm not sure if I'm seeing thing. I'm noticing the pattern of the item drop cycles.
At start, the first 2 drops give $ and then key. Then after that $,$,$,$? then blue gun (upgrade) then back to $ like 5 or 6 I think and blue gun drops after that, the cycles changes. However, as the cycle pattern changed, it goes $ first then Light bulb. if that have been picked up earlier before making a U-turn. It'll drop a 2nd key after the $ drop before REACHING to the first door to get a pack of invisible potion and then to the first sewer. then from there, there sometime there is a almost a HUGE gap of no drop when killing the blue frog. If not you might get at least 2 or 3 item drops then possible huge gap of no drops.
As I notice, I was watching the 2 runners that running this to get the key drop faster, when having level 3 gun power, it cycles when picking up the red and blue "gun" drop and key will drop a bit quicker. Sometime it makes a short gap or drops blue or red "gun" again to screw up the patterns when one of the red and blue are not picked up. It kind of like cycles back to that point that you didn't picked up then it screw things up as you try to get the pattern back in place.
I wasn't too sure if I was seeing thing how the item cycles when it drops. A lot people been telling me by saying " Man! The item drops are SO RNG! ¤sigh¤" and " This is some RNG BS and the item doesn't want to drop that stupid key (or any item they are waiting to drop) and it's taking too long to get it to drop! ¤rage¤" At some point, I realize it's not RNG to me but to them it is.
Please correct me if I'm just seeing thing or not.
So I have had a very similar feeling @MrPupG and have been thinking about looking into this myself as was really keen on looking a speed improvements but have defo felt that drops have a cycle. Have been thinking about running it slow but the same as I would at speed and noting down drops to see if there is a pattern. I would say defo not mad.....
So @ShiningDragoon looking at this more the best option is to stick with weapon 4 pick up no power ups or down and this will give fastest key drops???? Thoughts
So there are a couple ways of looking at this. R = Rank
R3 method It's 2 drops to R2, 6 drops to R3, and then 10 drops per key till end (except last is only 6) so 1 key getting to r3 (8drop) and then another 10 keys past that. so 8 + (10x9) + 6 for 11 keys 104 (This is the simplest method and easiest to fix if an accidental gun up is grabbed without the gun down, just adds 2 extra drops to gun down)
R4 method 2 drops to R2, 6 drops to R3, 8 drops to R4 (which gets you 2 keys on the way), and then 16 drops to get the 2 keys (from that point on). (I believe we need 11 keys?) so 16x4 for another 8 and then 12 to end. So 16 + 16x4 + 12 92 (This is a little more viable on pal due to shooting through walls but getting the third key if skipping enemies might be tricky before whip)
R5 method semi complicated requires whip. So same thing 16 drops to R4 (2 keys), and then you get 12 drops into R4 having the key and gun up on screen at the same time (1key) so 28 drops. R5 you then farm 12 drops into it (having whip and key on screen at same time to grab both) and you get 2 per cycle. So 3 keys 28 drops. and then the other 8 keys in R5. 28 + (12x4) for 11 keys 76 (Side benefit is that for this strat you only need 3 keys before the whip house in the first place. But farming after you get this is rough due to the slime spawns in the sewer where I farmed due to narrowness of passage making it easy to hit the wall, be blocked by a red, etc. So for NA at least, it is more difficult but possibly more rewarding.)
(Yell at me if my numbers are off lol)