So, did we really just witness the "greatest" or "best" opening weekend in NCAA Tournament history? It's hard to quantify these things, but I decided to give it a go anyway.

Recency bias is a powerful thing. So to thwart it, I went back and looked at the results of every first weekend dating back to 1985, when the field expanded to 64 teams. I used '85 as a cutoff because it affords a balance. Tournament brackets from then on have the same amount of opportunities for "true" upsets, which I define as a gap of five seed lines or more (i.e., the gap-of-five). While looking through for the best candidates, I added up the Sweet 16 seeds' total number. The higher the number, the more unpredictable the first two rounds.

I also looked at how many 13s, 14s and 15s won at least one game if not made it to the Sweet 16. Those runs don't come often. It helps a given year's case, for sure.

Additionally, losing two No.1 seeds before the second weekend is rare. That was taken into account as well. So was how many small-school teams from one-bid conferences pulled off upsets. The one thing about this weekend: We had a lot of lower-seeded teams move on, but seeing Florida State, Syracuse and Kansas State get into the regional semifinals doesn't make us gush the way Florida Gulf Coast, George Mason or Ohio did in the past.

There is one more element to consider. The most powerful influence on our memories are the images of buzzer-beaters over the years. The reality is they happen, but percentage-wise vs. games played? They're very rare. What I found interesting is that a lot of the first-weekend buzzer-beaters (or last-second shots) that spring to mind -- Georgia Tech in '92, Maryland in '03, UCLA in '95, Florida in '00, Western Kentucky in '08, Valpo in '98, Northwestern State and Tennessee in '06 -- came in years that weren't overrun with first-weekend calamity.

Before we get to the five wildest years, here are my honorable mentions:

2001: Underrated tournament. Its opening weekend was noisy. There were nine gap-of-five upsets in the first and second rounds. That doesn't include Gonzaga making the Sweet 16 as a No. 12 -- beating No. 13 Indiana State on along the way. No. 15 Hampton's win over No. 2 Iowa State is an enduring image from this tournament.



Underrated tournament. Its opening weekend was noisy. There were nine gap-of-five upsets in the first and second rounds. That doesn't include Gonzaga making the Sweet 16 as a No. 12 -- beating No. 13 Indiana State on along the way. No. 15 Hampton's win over No. 2 Iowa State is an enduring image from this tournament. 2004: Kentucky, the No. 1 overall seed, was overwhelmed by spunky No. 9 UAB. No. 1 Stanford was upended by No. 8 Alabama. Since the field expanded, only thrice have fewer than three No. 1 seeds made the regional semifinals. This is one of those three years. The other two made the main list. Two No. 2 seeds were bumped in the second round in 2004 as well: No. 7 Xavier knocked off Mississippi State; No. 10 Nevada beat Gonzaga. Pacific and Manhattan each won a game as No. 12 seeds that year too.

Kentucky, the No. 1 overall seed, was overwhelmed by spunky No. 9 UAB. No. 1 Stanford was upended by No. 8 Alabama. Since the field expanded, only thrice have fewer than three No. 1 seeds made the regional semifinals. This is one of those three years. The other two made the main list. Two No. 2 seeds were bumped in the second round in 2004 as well: No. 7 Xavier knocked off Mississippi State; No. 10 Nevada beat Gonzaga. Pacific and Manhattan each won a game as No. 12 seeds that year too. 2006: Remembered for George Mason's Final Four run, but strictly in terms of first weekend, it needs to be mentioned. Mason was a controversial at-large team, you may recall. It started off by beating Michigan State and UNC. Yet it wasn't even the lowest-seeded team in the Sweet 16 that season: No. 13 Bradley was. No. 14 Northwestern State won on its final possession over No. 3 Iowa. There were 10 upsets with teams separated by five or more seed lines (gap-of-five).

Remembered for George Mason's Final Four run, but strictly in terms of first weekend, it needs to be mentioned. Mason was a controversial at-large team, you may recall. It started off by beating Michigan State and UNC. Yet it wasn't even the lowest-seeded team in the Sweet 16 that season: No. 13 Bradley was. No. 14 Northwestern State won on its final possession over No. 3 Iowa. There were 10 upsets with teams separated by five or more seed lines (gap-of-five). 2011: Four (!) double-digit seeds made the Sweet 16: No. 10 Florida State, No. 11 Marquette, No. 11 VCU, No. 12 Richmond. That has only happened a few times. Plus, No. 13 Morehead State stunned No. 4 Louisville. Total number for seed lines by the Sweet 16: 80. No. 1 seeds went 8-4, their worst win percentage ever for a single tournament.

Four (!) double-digit seeds made the Sweet 16: No. 10 Florida State, No. 11 Marquette, No. 11 VCU, No. 12 Richmond. That has only happened a few times. Plus, No. 13 Morehead State stunned No. 4 Louisville. Total number for seed lines by the Sweet 16: 80. No. 1 seeds went 8-4, their worst win percentage ever for a single tournament. 2013: The year of Dunk City. Florida Gulf Coast's run to the Sweet 16 as a No. 15 made history. Really, it has a case as the more memorable run vs. UMBC -- but it's up to the ages to decide that. Give it a decade and we'll circle back. Also, Nos. 9, 10, 11, 12, 13, 14 and 15 seeds all won in this tournament. Harvard, a No. 14, took out No. 3 New Mexico in Salt Lake City (I was there). No. 1 Gonzaga was taken to the final minute by No. 16 Southern. No. 13 La Salle went from the First Four to the Sweet 16. Wichita State, a No. 9 seed, made the Sweet 16 and eventually the Final Four. Seed total: 81. Gap-of-five upsets: 10.

The year of Dunk City. Florida Gulf Coast's run to the Sweet 16 as a No. 15 made history. Really, it has a case as the more memorable run vs. UMBC -- but it's up to the ages to decide that. Give it a decade and we'll circle back. Also, Nos. 9, 10, 11, 12, 13, 14 and 15 seeds all won in this tournament. Harvard, a No. 14, took out No. 3 New Mexico in Salt Lake City (I was there). No. 1 Gonzaga was taken to the final minute by No. 16 Southern. No. 13 La Salle went from the First Four to the Sweet 16. Wichita State, a No. 9 seed, made the Sweet 16 and eventually the Final Four. Seed total: 81. Gap-of-five upsets: 10. 2014: Just barely missed the cut. Five teams seeded No. 7 or lower were in the Sweet 16. There were 10 gap-of-five upsets combined in the Round of 64 and Round of 32. Mercer knocked off No. 3 Duke, No. 10 Stanford beat No. 2 Kansas, No. 8 Kentucky beat undefeated, No. 1 Wichita State in one of the best second round games of all time. There were three 12-over-5s: Stephen F. Austin beat VCU in the final second; North Dakota State upset Oklahoma; and No. 12 Harvard took out No. 5 Cincinnati. Any time an Ivy League school wins, it seems to give the tournament a B-12 shot. Also, No. 11 Dayton moved on to the Sweet 16 (and ultimately the Elite Eight). That tournament had five overtime games in the Round of 64 -- that round alone set the tournament record for most overtime games in a year. Two No. 2s and a No. 1 were gone before the Sweet 16.

Those years don't even include 1991, '93 and '97 -- all of which were witness to No. 15s beating No. 2s. And 2000 is not listed here, because while it was a wacky tournament (two No. 8 seeds to the Final Four), the lowest seeded team to win a game that year was an 11. The first weekend was notable (nine gap-of-five upsets and only two No. 1s and two No. 2s making it to the Sweet 16) but not particularly dramatic.

Here are the six greatest/wildest opening weekends in since the tournament expanded in 1985.

No. 6: 2012

When you get two No. 15 seeds beating No. 2s, it must qualify. That's why I have a top six instead of a traditional top five. We might go decades before we see a pair of No. 15s (or a 15/16 combo) win first-round games again. That year, Norfolk State beat Missouri and Lehigh beat Duke. That alone warrants inclusion. There were eight gap-of-five upsets in the first weekend. VCU got past Wichita State in the Round of 64 -- then Indiana barely beat VCU two days later. No. 1 Michigan State was almost beaten by Rick Majerus' Saint Louis team in the second round. In the Midwest, No. 13 Ohio and No. 11 North Carolina State bust through to weekend No. 2.

Sweet 16 seed total: 73.

No. 5: 1999

What a great year. The regional semifinals had five double-digit seeds (three No. 10s, a No. 12 and a No. 13) -- but it also had all four No. 1s. No. 2 seeds went 5-4 that year, their worst win percentage ever. What stands out? No. 12 Southwest Missouri State made the Sweet 16 in the East. As did No. 10 Purdue. In the Midwest, No. 10 Oklahoma broke through and so did No. 10 Miami (Ohio). The West provided No. 10 Gonzaga's coming out party; it went to the Elite Eight that season, in effect jumpstarting the program's rise to national prominence. Gonzaga took out a terrific Stanford team in the second round. The West also gave us the Weber State stunner: The No. 14 Wildcats, with Harold Arcineaux, knocked off a star-studded No. 3 North Carolina team. Arcineaux's steal on UNC's final possession secured the upset. Kentucky and Kansas played to a 92-88 finish in overtime in the second round.

Sweet 16 seed total: 88.

No. 4: 2016

I almost put 2016 above 2018. It was just stupid that year. The seed total for the Sweet 16 wasn't high, but the results and finishes were bonkers. There were dramatic endings maybe you've already forgot about, like Providence winning on a last-second layup or USC or Notre Dame knocking out No. 14 Stephen F. Austin with a last-second tip-in. Cincinnati had a last-second dunk waived off and lost to Saint Joe's. In terms of a combination of disarray and drama, 2016 has a great case.

Then you had No. 12 Yale, in its first tournament since the early 1960s, beating Baylor. No. 14 Stephen F. Austin beat West Virginia in the first round. 2016 had nine gap-of-five upsets. Josh Hagins of Little Rock hit a fall-back jumper to send its game vs Purdue to overtime -- Little Rock won in double OT. Bronson Koenig's killer from the corner knocked of No. 2 Xavier in the second round.

Oh, right, and No. 15 Middle Tennessee pulled off what's now probably the second most shocking upset in tournament history. Despite being a 2, the Spartans were regarded by the majority as the strongest team in the field. It was a 15 over a 2 in ink but almost a 16 over a 1 in spirit.

STILL. NOT. DONE. Maybe I should have 2016 higher. Because we also have Texas A&M coming back from 12 down in the final 35 seconds of regulation to defeat Northern Iowa, which was the largest deficit with less than a minute remaining to be eradicated on the way to victory in the history of the sport. The Aggies tied the game on a layup with just under 2 seconds left, then won in double overtime.

Lastly, Paul Jesperson's half-court buzzer-beating bank shot that won it for Northern Iowa over Texas in the first round is to me one of the top three winners in tournament history. A casual-looking killer. Smack off the backboard and in. LOL at this:

Sweet 16 seed total: 66.

No. 3: 2018

The earth-shifting power of a No. 16 has to put this in the top three. UMBC's win, by 20 points over the No. 1 overall seed that was a 20.5-point favorite, is for eternity. So throw that in the pot first. Then you have two No. 1 seeds, two No. 2 seeds, two No. 3 seeds and three No. 4 seeds already out. This is why 2018's first weekend has a case for the best ever.

This #MarchMadness opening weekend was one for the ages. pic.twitter.com/KkoBShz4rX — CBS Sports (@CBSSports) March 19, 2018

Now consider the Cinderella factor. Loyola for sure is one. Nevada is more dark horse than Cinderella (yes, there is absolutely a difference), but either way both are into the regional semifinals and one will play in the Elite Eight. That boosts the cause.

Then, the finishes. Loyola hit two shots in closing seconds in consecutive games to get past major-conference competition Miami and Tennessee. The argument grows stronger still. Toss Michigan's buzzer-beater on top and, yeah, it's an all-timer. Then there's the stun factor: No. 1 Virginia, No. 2 North Carolina and No. 4 Arizona each lost by nearly or more than 20 points to UMBC, Texas A&M and Buffalo. All gap-of-five upsets. Speaking of gap-of-five upsets, this year we're at 10, which matches the most ever (with many other years in this column) in the first weekend.

This year's tournament is also the first time a regional lost all top four seeds before the Sweet 16. It's like Noah's Ark out there right now. We have a pair of 1s, 2s, 3s, 7s, 9s and 11s. There were 21 games decided by six points or less in the first and second rounds.

Special year. But two others beat it.

Sweet 16 seed total: 85.

No. 2: 1990

The year of Loyola Marymount. The Lions, seeded 11th, made a run to the Elite Eight mere weeks following star Hank Gathers' death after collapsing on the court. LMU memorably dropped 149 points (!!) on reigning champion Michigan in the second round. As I wrote above, a visual element can go a long way with creating the "best" NCAA Tournaments or rounds. The images of Bo Kimble shooting foul shots with his left hand to honor his late teammate are powerful.

The tournament that year had six teams seeded seventh or lower get to the Sweet 16. No. 2 seeds were a mere 5-4, matching their anemic run from 1999. There were 10 gap-of-five upsets ... and all of them came in the first weekend! Only one No. 2 seed made it to the regional semifinals.

Here's the most amazing part: 22 games in the first weekend were decided by FOUR points or less. Three went to overtime. An absolutely epic tournament, and in particular an elite first weekend full of frenzy. UNC made the Sweet 16 as an 8 seed. Texas got there as a 10. And Northern Iowa won as a No. 14 with this buzzer-beater over Missouri.

Sweet 16 seed total: 88.

No. 1: 1986

In terms of bracket ridiculousness and outright bedlam, '86 is still the champ. Some of this must be attributed to the fact that the selection committee in the early years of the 64-team field was obviously shooting at a moving target. Seeds were off with many teams because that was, truly, a much simpler time. But still, the '86 tournament overall brought chaos and drama. It holds the record for the highest seed total in the Sweet 16: 89. There were six teams seeded seventh or lower that made the Sweet. No. 3 seeds went 3-4. Gap-of-five upsets: 10.

Here's how wacky it got: No. 12 DePaul made the Sweet 16 after winning its first two games in the East Regional by a total of nine points. No. 14 Cleveland State beat No. 3 Indiana and No. 6 Saint Joseph's ... then played a seventh-seeded Navy team in the East Regional semifinals. Second seeds Michigan and Syracuse were bounced in the second round. Arkansas Little Rock won as a No. 14 over No. 3 Notre Dame. NC State and Iowa State played in the Sweet 16 in the Midwest Regional -- as a 6 and a 7.

LSU famously got to the Final Four that year. It was sub-.500 in the SEC but made the field, then Purdue in the first round before squeezing past Memphis State at the buzzer. Broken play mini miracle here.

I'm not done. No. 8 Auburn stunned powerhouse No. 1 St. John's in the second round of the West Regional. Fifteen first weekend games were decided by six points or less. This tournament was feral. It was raw. It was the seed that allowed for all future madness to take root.

Sweet 16 seed total: 89.

Hey, if 2018 is the best in your eyes, more power to you. But this rundown only reaffirms what everyone knows to be true: The NCAA Tournament is amazing every single year. Every tournament that's ever been held has at least a few moments that make it historic or noteworthy in some respect. At this point, 2018 is definitely making a run for the greatest Dance ever. Let's see what the next weekend can provide.