Why is the result of this "countifs" formula = 0? - excel-formula

Question

My goal is determine how many times a given teammate is matched up with another given teammate over 3 rounds of golf played by 3 different teams. The same roster of 12 players is changed up each round. The goal is to minimize the number of times the players are paired up with the same people over the 3 rounds.
I attempted to use the COUNTIFS formula in excel, but it returns 0 when checking if the name of each player is in the same "Team" range.
In my sheet, i have a table for players to show how many times they are paired up with different people in the 3 rounds. I can't even get it to calculate the matchup from Team 3 in Round 1 (Mike & Matt paired up), let alone move on to summing up the entire set of data.
From the screenshot you can see my equation =COUNTIFS(Q3:Q6,S3,Q3:Q6,T1) in cell T3, referencing the data in Q3:Q6 for the names Mike and Matt.
I've reviewed plenty of examples using COUNTIFS from other types of information/data types, so I don't understand why my formula fails. When I replace one of the cell references to a name with a wild card * then it returns a result of 1. If I take out one of the two references all together it returns a result of 1, for the player name that remains.
=COUNTIFS(Q3:Q6,S3,Q3:Q6,T1)
Q3:Q6 is the table I'm referencing at the moment. The same table is referenced for both players. S3 is Mike and T1 is Matt. Both players are listed in the reference range, so it seems to me that the condition is satisfied for both components.
I don't get any error messages, just a result of 0 when I'm expecting 1.

Answer 1

Because COuNTIFS() is AND not OR So the cell would need to be both Matt and Mike at the same time, which is not possible.
To do OR we need to do something slightly different:
=SUMPRODUCT(COUNTIFS(Q3:Q6,CHOOSE({1,2},S3,T1))
This will return 2 if both are in the range so to get it to 1 we do:
=--(SUMPRODUCT(COUNTIFS(Q3:Q6,CHOOSE({1,2},S3,T1))=2)
Which will now return 1 if both are found in the range and 0 if only one or none are found.
So we can string 9 of these together to get the output you want:
=(SUMPRODUCT(COUNTIF($M$3:$M$6,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($O$3:$O$6,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($Q$3:$Q$6,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($M$10:$M$13,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($O$10:$O$13,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($Q$10:$Q$13,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($M$17:$M$20,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($O$17:$O$20,CHOOSE({1,2},T$1,$S2)))=2)
+(SUMPRODUCT(COUNTIF($Q$17:$Q$20,CHOOSE({1,2},T$1,$S2)))=2)
It will now count how many times the pairs were on the same team: