In fact, their five-game loss to the Sabres last spring laid the foundation for the Senators' current success.
"We feel like we could have done more damage," Senators captain Daniel Alfredsson said Tuesday, recalling the second-round loss that sent his team home earlier than expected. "And I think that's the way we're playing this year."
With Ottawa and Buffalo set to open the best-of-seven Eastern Conference final series Thursday at HSBC Arena (8 p.m. ET), last year's defeat to the Sabres is still fresh in the Ottawa players' minds.
Without that loss, the Senators would likely not have undergone the transformation from a free-scoring team that lacked a killer instinct and couldn't handle close games a year ago to a disciplined, tight-checking team that's squeezed the life out of the opposition so far in the playoffs.
"This time around, we are a better defensive team so if we get up in a game, we're better suited for that," Alfredsson said.
A year ago, the Senators rode their high-powered offence through the regular season and racked up 52 victories and 113 points - both tying franchise highs. When the post-season began, their freewheeling continued with a five-game romp over the Tampa Bay Lightning in the opening round.
Against the Sabres in Game 1 of the second round, however, things unravelled - fast.
Ottawa blew five leads, two in the third period, en route to a 7-6 loss in overtime. The rest of the series, the goals that flowed so easily during the season had dried up and with along with them the chance to cover up any holes in their defensive game.
The Senators also proved incapable of grinding out close games. When things were tight, they couldn't produce when they needed to, losing all four games to Buffalo in the series by a goal, three times in overtime.
"We faced adversity and didn't know how to deal with it properly," Senators centre Mike Fisher said Tuesday. "It was a disappointing season last year because of it."
For coach Bryan Murray, the defeat was the sign that things needed to change during the off-season.
"The learning curve took place after the playoffs last year when we realized things had to be different," he said Monday on a conference call with reporters.
When Ottawa returned to training camp in the fall, they did so with an approach based more on a blue-collar work ethic than the previous red-light brigade.
The Senators still wanted production from top-line players such as Alfredsson, Dany Heatley and Jason Spezza, but not at the expense of giving up quality chances at the other end - which had killed them in the series against the Sabres.
The results, may have been slow to come judging from the Senators' start to the season, but they eventually did follow.
In these playoffs, the Senators patiently used a counter-attacking style to knock off the Pittsburgh Penguins and the New Jersey Devils in just 10 games total.
With a record of 6-0 when scoring first, the Senators have learned to protect leads and they no longer panic when games are close, going 4-2 so far in one-goal games.
"From Day 1, the coaches talked about what kind of team we wanted to be," Senators defenceman Wade Redden said Tuesday. "We still scored a lot of goals, but we focused a lot on playing a team game and there were different times during the year that we got into those tight games and were able to just stick with the program and not force things."
The killer instinct is also apparent in the way the Senators turned in arguably their best performances in each of their first two series in elimination games - a 3-0 shutout of Pittsburgh at home and a 3-1 road win at New Jersey.
"Last year, we were guilty of trying to force plays and go for that home-run play, where this year we're a little more patient and that's the way you've got to be at this time of year," Redden said.
The change in style has resulted in the Senators' ability to change their playoff fortunes. Chronic underachievers at this time of year, their history of failure in the post-season has been erased by making the trip to the conference final for just the second time.
Sabres coach Lindy Ruff has noticed the difference in the Senators this year.
"If that history (of failure) would've played into it, they probably would've went out in the first or second round," Ruff said. "You have to give them credit, there's been no history right there."