I was taught to "bid to make." That is, it would take 26 points to bid a game that was at least a 2 to 1 favorite to make. (I'd bid game with 24-25 only with "something extra" such as a solid five card suit that would take a disproportionate number of tricks.) Under these cirumstances, I would shun finesses (a 50-50 proposition) except as a last resort, because they "average down" my theoretical "67%" chances. Instead, I would look for an endplay, squeeze, or maybe a combination play (e.g. a drop play for 3-3 distribution in a key suit followed by a finesse.))
The IMP scoring table allows bidders to come out ahead if they make as many as 40% of the game contracts they bid. Hence, many players will now bid a speculative game with 22-24 points (instead of 26). More to the point, this result is occurring more frequently because of pre-emptive and "competitive" bidding, where the slightly stronger partnership is pushed into a game contract, instead of being allowed to stop at the three level. In this situation, a 50-50 shot at a successful finesse will "average up" their chances.
Do good players play finesses more frequently to "shorten" the odds when they are in long odds contracts with less than 25-26 points? In finance terms, do good players regard finesses as "dilutive" when they have 26+ points and "accretive" when they have 22?