Well then, lets say I am 4.8 to 1 to improve on the turn. Does that simply mean that I need to be getting 4.6 to 1 on my bet (investemnt)?
On an irregular basis, you can see where getting in with less
pot odds than the odds of improving your hand enough to win (remember most odds are based on improvement and offer NO guarantees), will, in the long run be -ev.
For practical purposes (and simplicity) lets think 25% chance (by the river) to improve a 4straight on the flop to a real straight . For this discussion I will ignore the possibility of pairing up to a winning hand, and only use the str8 draw part of my mental calcs.
Pot starts at 100 villain pots it, making the pot 200, and your call will be 100. This is 2 to 1 odds with a 4-1 hand. Not good. If a 2nd villain calls, making the pot 300, u would be getting 3 to one odds on a 4-1 hand. Still not a good thing. But at this point you can sometimes take your experiences (reads) about your villain(s) into account and deal with implied odds. Still generally gonna be -ev.
At lower level games my experience is that most players don't pot the bet, they will come in underbetting (generally), so in the above case lets say into that 100 pot, villain #1 only bets 25. Your call is 25 to make 125, and is 5-1, with a 4-1 hand. No brainer to call here. With a 2nd villain who calls, your odds jump to 6-1, etc etc.
Morale of this scenario; Seek situations that give you bigger pot odds than your hand odds to improve.
There are many many players who make decision down to decimal point odds. The situation above is grossly simple.
If I we include pairing up on the turn and/or river, your odds jump into the 30-35% range, depending on how many villains are sticking around.