ST. LOUIS -- The end result was not exactly indicative of how the Western Conference First Round series between the St. Louis Blues and Chicago Blackhawks was played out, but in the end, it's another disappointing and bitter pill for the Blues to swallow with an early Stanley Cup Playoffs exit.

Though their season ended with a 5-1 loss in Game 6 on Sunday, where the Blackhawks broke the game open with four third-period goals, four of the first five games were decided in overtime and Game 3 was a down-to-the-wire 1-0 game until Chicago added an empty-netter.

The series was a brand of contrasting styles, with the defending Stanley Cup champions going more for skill against the Blues' grit and physical nature.

The Blues lost the series 4-2 in similar fashion to the way they lost in the first round in 2013 against the Los Angeles Kings. Here are five reasons the Blues are again on the outside looking in:

1. Lack of goal scoring

The Blues scored 10 goals in their six games against the Kings a season ago and thought they addressed a need for a playmaking center by signing Derek Roy to a one-year, $4 million contract. Although Roy is not the sole reason here, he wasn't an offensive factor at all, and the Blues finished with 14 goals in six games against the Blackhawks. Only six of them came in the four straight losses to end the series.

Part of the problem was an ineffective power play, which went 2-for-29 in the series (both goals scored by Vladimir Tarasenko). Tarasenko (four) and T.J. Oshie (two) were the only players to score more than one goal in the series.

Many of the Blues' forwards played with injuries sustained late in the regular season, but as captain David Backes pointed out, "The result is not what we desired and we have to be better, and that starts with myself."

Backes, who missed two games in the series with an upper-body injury and broken left toe, Jaden Schwartz, Roy, Alexander Steen, Patrik Berglund and Oshie finished with four goals and 10 points between them.

The Blues were within one shot of winning each of the first five games in the series, and although they got the desired result in Games 1 and 2, scoring at the opportune time was not there moving forward. It's something that needs to be addressed moving into the offseason.

2. Miller factor

The Blues traded for goalie Ryan Miller to be the final piece to the puzzle in what they thought would be a Stanley Cup run. They paid a hefty price (goalie Jaroslav Halak, power forward Chris Stewart, prospect William Carrier and draft picks) for Miller and left wing Steve Ott.

Despite a six-game losing streak (in which Miller lost five) to end the regular season, Miller played well for the Blues. And although he doesn't deserve to shoulder all of the blame for this first-round exit, he never provided the consistent lights-out save the Blues were counting on to outplay Chicago's Corey Crawford, who stole a Game 3 victory for the Blackhawks and stopped 36 shots in Game 6 Sunday.

Miller finished 2-4 with a 2.70 goals-against average and.897 save percentage in the series, and for a guy brought in to be the missing piece to the puzzle, those are puzzling numbers.

"I'll have to sit down and think about that," Miller said when asked to assess his series. "I don't know, not good enough, I guess."

3. Toughness in the right areas

The Blues hit everything in sight against the Blackhawks. But hitting and checking are two different animals, and channeling those plays are what allowed the Blackhawks to score at critical junctures.

The Blues outhit the Blackhawks 228-143 in the series (an average of 38-24), but when it came down to it, there was never enough consistent physical checking inflicted on the likes of Jonathan Toews, Patrick Kane and the Blackhawks' skilled forwards.

Toews finished with seven points in six games and Kane had six points in six games, and the two were able to display their skill with the puck in the Blues' zone far too often without taking any contact.

Toews' overtime game-winner in Game 5 turned the series in Chicago's favor and ultimately gave the Blackhawks the chance to deliver the knockout blow at home in Game 6.

"Our game is based on making [the Blackhawks] stop and play," Blues coach Ken Hitchcock said prior to Game 6. "… When they're able to play on the move, and they're able to play on the move with transition, they are as dynamic as anybody in the League or better than anybody in the League. When we make them stop and have to play, we are really good at our game."

The Blues failed to make the Blackhawks stop and play consistently enough.

4. Backes' influence

When Blackhawks defenseman Brent Seabrook delivered an illegal check against Backes late in the third period of Game 2, it sent a rippling effect throughout the Blues locker room.

Although the Blues played arguably their best game of the series in a 2-0 Game 3 loss and were leading 3-2 late in Game 4 (in which they ultimately lost 4-3 in overtime), losing Backes' leadership, gamesmanship and strong two-way game was something the Blues had a hard time overcoming in the end.

Backes, who returned by Game 5, played big minutes and would never ask off any situation the team would want from him, but it was obvious the toe injury sustained after being hit by Steen's shot April 8 against the Washington Capitals never fully healed, and then the head/neck injury from the Seabrook blow was something difficult to overcome.

In typical Backes fashion, he accepted his share of blame when the series was over. Backes finished with one assist in four games.

"I'll take more than my share of the blame. I didn't produce," Backes said. "I'm counted on to produce. I'll shoulder that and think about it a lot this summer, and hopefully drive the engine going into next year."

5. Critical mistakes

Against a skillful team like the Blackhawks, limiting the mistakes is highly advisable. And when push came to shove, the Blues made more than their share of errors throughout the series.

Those mistakes didn't cost them winning the first two games, but in Game 3, Miller allowed a soft goal to Toews that turned out to be enough for Crawford to stymie the Blues. Late in Game 4, with the Blues holding onto a 3-2 lead, they failed to clear the zone and the crease on Bryan Bickell's game-tying goal with 3:52 remaining. In Game 5, a fortuitous bounce occurred on Toews' game-winner in overtime, but a poor defensive line change enabled the Chicago captain to get a breakaway. And in Game 6, Chicago's second and third goals that ultimately sealed the Blues' fate came as a result of technical errors.

"It's frustrating," Blues defenseman Barret Jackman said. "I think at times Chicago beat us, and I think at times, we beat ourselves. There were some mistakes that we made that cost us. … The series could have gone either way, but it's a tough pill to swallow."