Transfer season is in full swing now that the college basketball season is officially over.

If you have been watching Twitter, you’ve seen a flurry of transfer announcements in recent days, from freshmen leaving after one year to graduates looking for a sixth season. The tweets all follow a similar script: a player thanks coaches and teammates for his time at the school, and then declares that he is entering the transfer portal.

Northwestern figures to be an active portal participant this year. They lost Tydus Verhoeven, a transfer himself who is out of eligibility, and Julian Roper II, who announced his intent to go a-portaling last week, from the team that made the NCAA Tournament for just the second time in school history.

Then on Sunday came the big blow, when star point guard Boo Buie declared for the NBA Draft – though he left the door open to a possible return by maintaining his college eligibility. Buie’s backcourt mate, Chase Audige, must make the same decision about whether to return to Evanston for his “free” COVID year of eligibility or move onto the pro ranks. Same with Robbie Beran.

The Wildcats have three Class of 2023 recruits coming in next season: guards Jordan Clayton and Parker Strauss, and wing Blake Barkley. But the addition of those three freshman means Northwestern will have just 10 scholarship players and three open slots next season, even if both Audige and Beran opt to return. If those two move on to the next level, they could have as many as five scholarship spots up for grabs.

So the Cats have some work to do.

A couple of players who recently announced their entry into the transfer portal have connections to Northwestern. Freshman Ben Shtolzberg had an offer from the Wildcats and took an official visit to NU before opting for Creighton. Baylor guard LJ Cryer is the older brother of incoming freshman linebacker Juice Cryer.

While we don’t know what the future holds for those players, or other potential targets in the portal, we can look back at what Northwestern has done in the past. And despite facing some significant academic restrictions that other programs don’t, head coach Chris Collins has managed to add several impact transfers over the course of his career.

Not surprisingly, six of Collins' eight transfers were graduates -- mostly because it's easier to get a graduate past admissions. (We won’t count one transfer he had on his roster in his first year because Nikola Cerina was inherited from previous coach Bill Carmody’s tenure.)

Four of those eight turned into starters. One of them turned into a bona-fide star. That's a pretty good track record.

Collins had at least one transfer on every team but one during his time in Evanston – the 2016-17 NCAA Tournament team. He had one team, in 2019-20, that featured three transfers on the roster, and two that started every game.

So let’s look back at Collins’ transfers at Northwestern, in order of their impact.

Seasons: 2020-21, 21-22, 22-23

NU career averages: 12.3 ppg, 3.7 apg, 2.3 rpg, 2.0 spg

The gold standard of Northwestern transfers, Audige came to NU after one year at William & Mary. He had to sit out the 2019-20 season due to NCAA rules (you had to do that back then), but then started 81 of 82 games over the next three years, scored more than 1,000 points and established himself as one of the best two-way guards in the Big Ten, if not the nation.

A streaky but prolific scorer, the 6-foot-4 Audige was able to carry the Wildcats at times offensively. He scored a career-high 28 points against DePaul in December, and then went off for 10 points in the last four minutes to lead the Wildcats to a stunning upset of No. 1 Purdue in February. He was the team's second-leading scorer this past season, averaging 14.1 points per game.

But Audige's greatest strength was on the defensive end. An outstanding athlete, he was always a good defender; he turned himself into an elite one as a fifth-year senior. He won the co-Big Ten Defensive Player of the Year award and earned second-team All-Big Ten honors this season while leading Northwestern to its second-ever trip to the Big Dance.

Season: 2019-20

NU career averages: 10.4 ppg, 4.1 rpg, 3.9 apg

Collins showed his creativity and willingness to take a chance when he added Spencer as maybe the most unique grad transfer in college basketball history in 2019. Spencer had played lacrosse for four years at Loyola-Maryland, winning the Tewaaraton Trophy, the lacrosse equivalent to the Heisman, in the process. Then, he decided he wanted to play a sport he hadn't played competitively since high school and found a home at Northwestern. Collins was glad he did.

A feisty, physical competitor, Spencer started 29 of 31 games and finished as the team's No. 2 scorer and rebounder, and was No. 1 in assists. He had some growing pains but often was the best player on a very bad Northwestern team that finished 8-23 (3-17 Big Ten).

Spencer is still chasing his basketball dream; he has played in the NBA G League for the last two seasons.

Seasons: 2018-19, 19-20

NU career averages: 6.6 ppg, 2.3 rpg, 2.2 apg

Turner transferred to Northwestern after two years at Boston College. After sitting out one season, he started 20 games in 2018-19, and then assumed the sixth man role for the Wildcats in 2019-20.

A slashing 6-foot-7 wing, Turner was not a great shooter but could get to the rim. He averaged an impressive 27.2 minutes per game in his career, showing his value and his versatility. He was capable of the occasional double-digit scoring output but never tallied more than 12 points in a game. He added value as a rebounder and a defender, and even ran point for the Wildcats in a pinch.

Season: 2021-22

NU career averages: 3.3 ppg, 2.1 rpg

Williams is an Evanston native who decided to come back home as a grad transfer after four years at Fairleigh-Dickinson. A crafty big who was much more athletic than his 6-foot-7, and egregiously underlisted 220-pound frame would lead you to believe, he gave Northwestern some size and production off of the bench in a rotation with Pete Nance and Ryan Young.

Williams played in all 29 games and made one start for the 2021-22 Wildcats. He averaged 12.9 minutes per game and reached double figures in scoring just once. But he provided rebounding, a physical presence in the paint and the occasional putback or deft pass off of an offensive board. A perpetually smiling and happy player, Williams always gave the team energy when he stepped on the floor.

Season: 2022-23

NU career averages: 2.4 ppg, 2.6 rpg

Despite decidedly unimpressive stats, Verhoeven played a valuable role for one of the best teams in school history this season. A very under-the-radar grad transfer from UTEP, Verhoeven started the first nine games of the season until center Matt Nicholson was ready to move into the starting job. Then he was the No. 2 that became critical once freshman Luke Hunger was lost for the season.

The 6-foot-9 Verhoeven wound up playing 15.8 minutes per game, and while he averaged fewer than three points and rebounds per game, he gave the team valuable minutes, five additional fouls and defensive versatility. He was a consummate "glue guy" for the Wildcats who played in all 34 games and came up with the rare bucket when they needed it.

Season: 2018-19

NU career averages: 9.8 ppg, 1.9 rpg

Taylor's relatively low ranking on this list for a double-digit scorer is due to his failure to live up to expectations. The leading scorer in the Missouri Valley Conference as a senior at Evansville (21.3 ppg), Taylor was one of the most sought-after guards in the portal and seen as a major coup for the Wildcats.

Even though he started all 31 games and averaged 10 points in his lone season in purple, he was a disappointment as a shooter, forcing us to rank him behind players with much more modest numbers. Taylor started his NU career by hitting six three-pointers and scoring 20 points in the season opener, looking every bit like the scorer the Cats desperately needed. But he proved to be a very inefficient player, a long-distance marksman who shot just 33.3% from beyond the arc and 35.3% overall.

Season: 2015-16

NU career averages: 3.6 ppg, 3.3 rpg

Van Zegeren came in as a grad transfer big man after four years at Virginia Tech. At 6-foot-10 and 235 pounds, he certainly looked the part, and he added some energy and athleticism to NU's frontcourt.

JVZ played more than 20 minutes just three times and hit double figures in scoring just once. He was a decent backup big behind a freshman Dererk Pardon and starter Alex Olah.

Season: 2014-15

NU career averages: 1.0 ppg, 1.2 rpg

Collins' very first transfer was his least effective one. Kreisberg was a 6-foot-10 center who transferred as a graduate after four years at Yale, and he generally looked a player better suited to the Ivy League.

Kreisberg wound up averaging just 6.5 minutes per game in mop-up duty behind Olah and a young Gavin Skelly. His season highs were six points and four rebounds, in different games, and he never played more than 15 minutes in any contest