RFM question now that bid day is here

[Lagniappe]

DD gets her bid in a few hours, so I'm curious about how this works under RFM (not counting being placed as a QA). Quota at her school was 87. She preffed 3 houses and ranked them 1, 2, and 3. If she's in sorority 1's top 87, does she automatically get placed there? If she's not on their list but she is in sorority 2's top 87, does she go to sorority 2? What if sorority 3 has her ranked somewhere higher on their list than either of the other two houses? Or is it not that simple of a process?

[AZ-AlphaXi]

Its not that simple. Think of the first bid list like a box. The number of PMs that is quota goes into the box. You don't come out of the box until you match somewhere.

So if you are in sorority #1's top 87 you get a bid there. However, you don't move to looking at your 2nd choice until your first choice reaches quota. So, for example, you are #90 on your first choice's list. You might not match during first pass, but if/when 3 pnms that are in their first 87 get bids elsewhere, you at #90, get moved onto the bid list ie go into the box. The next time through the pms you match at your first choice.

So it doesn't matter where you are on your second or third chapter's bid lists, you continue to attempt to match to your first choice, until they make quota. Then, and only then, does the process move to looking at your second choice. The process then starts over with the second choice.

[ladybug12]

Originally Posted by AZ-AlphaXi

Its not that simple. Think of the first bid list like a box. The number of PMs that is quota goes into the box. You don't come out of the box until you match somewhere.

So if you are in sorority #1's top 87 you get a bid there. However, you don't move to looking at your 2nd choice until your first choice reaches quota. So, for example, you are #90 on your first choice's list. You might not match during first pass, but if/when 3 pnms that are in their first 87 get bids elsewhere, you at #90, get moved onto the bid list ie go into the box. The next time through the pms you match at your first choice.

So it doesn't matter where you are on your second or third chapter's bid lists, you continue to attempt to match to your first choice, until they make quota. Then, and only then, does the process move to looking at your second choice. The process then starts over with the second choice.

I think this is the best, most concise explanation of how bid matching works that I have ever read! Love the box analogy!!!

[33girl]

Originally Posted by ladybug12

I think this is the best, most concise explanation of how bid matching works that I have ever read! Love the box analogy!!!

Call it, thinking inside the box.

[DeltaBetaBaby]

Originally Posted by AZ-AlphaXi

Its not that simple. Think of the first bid list like a box. The number of PMs that is quota goes into the box. You don't come out of the box until you match somewhere.

So if you are in sorority #1's top 87 you get a bid there. However, you don't move to looking at your 2nd choice until your first choice reaches quota. So, for example, you are #90 on your first choice's list. You might not match during first pass, but if/when 3 pnms that are in their first 87 get bids elsewhere, you at #90, get moved onto the bid list ie go into the box. The next time through the pms you match at your first choice.

So it doesn't matter where you are on your second or third chapter's bid lists, you continue to attempt to match to your first choice, until they make quota. Then, and only then, does the process move to looking at your second choice. The process then starts over with the second choice.

Continuing the analogy, if you are on #2's bid list (first 87 when quota is 87), you are in the box, and can only be moved out of the box if you match to #1. It's not as though #2 can fill its box without you while you are waiting around to see what happens at #1. If you are high enough on #2's bid list to receive a bid, the ONLY WAY you don't get a bid from #2 is if you match to #1. This is the myth of "cross-cutting."

All of which is to say that, when it comes to final preference rankings, you should list them in true preference order, there is no reason to be strategic about what would give you the best chances to get a bid.

[carnation]

Some people think that cross-cutting is a myth. It existed in a big way pre-RFM. This happened when a girl would rank sorority A as #1 and B as #2 but she would be on B's first list and A's second one. Girls would end up bidless some of the time.

[DeltaBetaBaby]

Originally Posted by carnation

Some people think that cross-cutting is a myth. It existed in a big way pre-RFM. This happened when a girl would rank sorority A as #1 and B as #2 but she would be on B's first list and A's second one. Girls would end up bidless some of the time.

I don't doubt that there were schools that didn't follow standard bid matching procedure pre-RFM, but if they did, what you described could not happen. Going bidless meant she wasn't high enough on either list. If she had ranked B as #1 and A as #2, she still would have been bidless.

[carnation]

Originally Posted by DeltaBetaBaby

I don't doubt that there were schools that didn't follow standard bid matching procedure pre-RFM, but if they did, what you described could not happen. Going bidless meant she wasn't high enough on either list. If she had ranked B as #1 and A as #2, she still would have been bidless.

I watched it happen several times during very closely monitored hand matching. Had the girl put A as her number 1 and B as her number 2, she would have matched. As it was, both filled up before she matched. Quota was set before prefs back in the day so many girls went to the maximum number of prefs, listed all their parties, and still didn't get bids.

Also, there were no QAs. Come to think of it, a lot of women today would go bidless without QAs.

[tcsparky]

I'm a little confused. If she was on B's first list, then B could NOT have made quota before getting to her name.

She would have had to be on both group's second list and they both reached quota before getting to her name, regardless of how she had listed them.

Originally Posted by carnation

Some people think that cross-cutting is a myth. It existed in a big way pre-RFM. This happened when a girl would rank sorority A as #1 and B as #2 but she would be on B's first list and A's second one. Girls would end up bidless some of the time.

[carnation]

Oh man. I am not explaining this well but I know exactly what I mean! It's all in the order she listed them in her card.

[Loyally Kappa]

Originally Posted by DeltaBetaBaby

Continuing the analogy, if you are on #2's bid list (first 87 when quota is 87), you are in the box, and can only be moved out of the box if you match to #1. It's not as though #2 can fill its box without you while you are waiting around to see what happens at #1. If you are high enough on #2's bid list to receive a bid, the ONLY WAY you don't get a bid from #2 is if you match to #1. This is the myth of "cross-cutting."

All of which is to say that, when it comes to final preference rankings, you should list them in true preference order, there is no reason to be strategic about what would give you the best chances to get a bid.

Being a math nerd, I think I am going to attempt to make a video of how bid matching works so that folks can "see" it. I always say, "If you cannot make the math visible, you don't understand it."

[als463]

Originally Posted by Loyally Kappa

Being a math nerd, I think I am going to attempt to make a video of how bid matching works so that folks can "see" it. I always say, "If you cannot make the math visible, you don't understand it."

Seriously though, I think this would be an awesome idea. I sure hope you do it.

[Loyally Kappa]

Originally Posted by als463

Seriously though, I think this would be an awesome idea. I sure hope you do it.

I will! Give me a little time, some colored Post-It Notes, a blank wall and then watch me! The thing about a preferential bidding system is that it is like an invisible sieve "in motion" at all times until matches are exhausted, so unless you can "see" the sieve and the movement, it is a bit mysterious.

I need to decide upon an adequate number of sororities and PNMs to do the trick. It doesn't have to be a lot, but it needs to be enough!

[LAblondeGPhi]

Originally Posted by AZ-AlphaXi

Its not that simple. Think of the first bid list like a box. The number of PMs that is quota goes into the box. You don't come out of the box until you match somewhere.

Originally Posted by Loyally Kappa

Being a math nerd, I think I am going to attempt to make a video of how bid matching works so that folks can "see" it. I always say, "If you cannot make the math visible, you don't understand it."

Bah! I love this idea! Ok, so I got so into it that I wound up making a gif using AZ-AlphaXi's awesome box explanation:

[chi-o_cat]

That example is awesome!

I sort of feel sorry for Diana, though, for being the only PNM not to get her first choice.