Basic Card Odds

Hi,

I'm posting mostly to verify if I'm working out card odds correctly. I looked online for information and get conflicting ideas. Here's what I mean:

(I can't post links yet so I'm just including the title of the sources)
1) YouTube: WSOP Academy (Chapter 3) - Lesson 03 - Determining Pot Odds (2:11-3:00)

2) cardschat: Poker Odds for Dummies (part 3)

They are explaining card odds with pretty much the same situation but 1) is calculating the odds by comparing the outs to how many cards remain in the deck at a given time, while 2) is comparing the outs to how many cards don't help improve the hand.


(if you don't check out the links, the situation is very similar in both, four to a flush with only the river left to come, what are the card odds. 1) uses 9 outs and 46 cards left in the deck to get to roughly 5:1 odds, and 2) use 9 outs and 37 cards that don't complete the draw to reach roughly 4:1. Which is correct?)

~19.6% or about 4:1 (see link below)

https://www.pokernews.com/poker-tools/poker-odds-calculator.htm

***: 5:1 odds is wrong, if that is what the website says (i didn't check it,but they may have meant $5?).