Tried to analyze the effectiveness of my execution algo, looks like it has some benefits (though it's a very crude analysis and I might've messed something up). This is cumulative sum of execution profits and losses from the "worst" side of the spread to the actual fill (current ask-fill if I'm buying, fill-bid if selling). (it can't achieve mid-point execution, but it seem to do better than giving away full spread every time):
View attachment 256261
So looks like I made about 600$ in the last year or so compared to executing on the worst side of the spread.
Although the large positive jumps look strange, this thing should have negative skew, so small frequent gains and large rare losses, the large rare gains are weird. Probably some edge-cases like a lost connection or something, maybe I'll investigate them more closely..