I'm launching a new series today called The 7. It's pretty simple: pick a topic and find seven things to talk about. I wanted the first one to be about the specialty jerseys worn in the NHL during the 2017-18 season. As luck would have it, there were exactly seven.

With Adidas taking over as the sole manufacturer of NHL game jerseys in 2017-18, the league opted to lighten their load by dispensing with third jerseys for a year. It meant a lot less variety on the ice, but there have been a few occasions for teams to don something different.

1 // Senators · NHL 100 Classic

On Dec. 16, the league wrapped up its year-long centennial celebration with the NHL 100 Classic, staged outdoors at TD Place Stadium in Ottawa. The Senators took on Montreal while sporting a red version of the heritage jersey they launched in 2011. The Sens won 3-0. They've since worn the sweater seven more times during the regular season — nearly making it a de facto third jersey.

The more detail-oriented among us may be interested to know two changes were made to the non-event version of this jersey. First, the NHL 100 Classic patch was removed, as you'd expect. Second, the name font on the back was changed to the one used on the Sens' regular home jersey — but only for four of those games. For the last three, they went back to the narrow font used at the outdoor game. Not really sure why.

2 // Canadiens · NHL 100 Classic

There's not nearly as much to say about Montreal's uniform at the NHL 100 Classic. They stripped down their standard road sweater and added some silver. Then they got shut out by Ottawa while wearing it. But it's been a rough season overall for the Habs, so let's not blame the jersey. They haven't worn it again since.

3 // Sabres · NHL Winter Classic

As the new year arrived, Buffalo hosted the Rangers for the 2018 NHL Winter Classic at Citi Field — just 10 miles away from Madison Square Garden. But we won't get into why this was designated a home game for the Sabres right now. It's enough to say they had a white uniform that made us all wish they'd go back to royal blue full time again. Fingers crossed.

The Sabres lost that game in overtime but went on to wear their Winter Classic jersey two more times in February — for home games in their own city. They beat the Islanders 4-3 and fell to Washington 3-2. It was the only event sweater to pick up a win, loss, and an OT loss this season.

4 // Rangers · NHL Winter Classic

One of my favorite jerseys on this list is what the New York Rangers wore for the 2018 NHL Winter Classic. Inspired in part by the sweater used during the club's inaugural season in 1926, it's a classic look. It also led them to a 3-2 overtime victory at Citi Field.

Like Buffalo, the Rangers wore their Winter Classic jersey two more times at home during the regular season, but those games didn't go nearly as well. New York lost 4-0 to Toronto and 6-1 to Boston. Hope that's not a death sentence for these sweaters though. I'd love to see them back again next season.

5 // Capitals · NHL Stadium Series

The final outdoor game of the season took place on March 3 — the 2018 NHL Stadium Series at the U.S. Naval Academy in Annapolis, Md. The Capitals hosted Toronto while wearing blue jerseys for the first time since 2000, their nickname emblazoned across the chest. The home team skated to a 5-2 victory.

A few weeks later, the Caps wore their Stadium Series sweater indoors as they beat the Stars 4-3.

6 // Maple Leafs · NHL Stadium Series

Facing Washington in the 2018 NHL Stadium Series, the Maple Leafs went all white. And I do mean all. That included white gloves and even white pants. The only thing players wore that wasn't white was their skates. But all that white wasn't enough for them to sneak by the Caps as they lost 5-2.

The Leafs haven't worn that Stadium Series jersey again, but they were the only team to have two specialty jerseys this season.

7 // Maple Leafs · Next Century Game

While the NHL 100 Classic marked the start of the league's next century, the Maple Leafs did the same in their own way with the Next Century Game. On Dec. 19, the club dressed much like they had 99 years earlier when they were known as the Toronto Arenas. That makes this jersey the only true throwback worn during the 2017-18 season. The Leafs had a goal explosion that night as they defeated the Hurricanes 8-1.

That wraps up the first edition of The 7. Nothing to crazy, but I hope to make something more out of it going forward. Speaking of which, I'm always open to ideas!