Game 4 of the NLDS shapes up as a defining moment for Clayton Kershaw

Los Angeles Dodgers ace Clayton Kershaw is widely considered the best pitcher in baseball. We'll make no argument to the contrary.

Kershaw's performance over the past four seasons has been without peer. This year, he finished 21-3 with a 1.77 ERA. He claimed his fourth consecutive National League ERA title, and that 1.77 mark was nearly half a run better than his closest competitor. He is a lock to win his third NL Cy Young award in the last four years.

Kershaw had a 1.83 ERA during the 2013 campaign, so that means he is just the second pitcher in the live-ball era to post an ERA of 1.85 or less in consecutive seasons. Hall of Famer Greg Maddux is the other.

Yes, Kershaw is the best in the game right now.

But you know what has eluded him to this point in his career? Postseason success. I've heard some people compare Kershaw to another former Dodgers' lefty, Hall of Famer Sandy Koufax. Some say Kershaw may go down as the best pitcher to play in the live-ball era once he's all done. Who am I to say he can't do that? But if he is going to be considered better than Koufax, he better figure out a way to beat the St. Louis Cardinals in the playoffs.

The Cardinals will take a 2-1 series lead over the Dodgers into Tuesday's Game 4 of the National League Division Series. Kershaw is taking the ball on three days' rest. The season is on the line for the favored Dodgers.

Normally, a team feels pretty good about sending its ace out there in a must-win game, but Kershaw's postseason numbers are inexplicably terrible.

In 10 postseason games (7 starts), he's 1-4 with a 5.20 ERA. He has lost each of his last three playoff starts, all against the Cardinals. In two of those outings, he got bombed.

Kershaw went to the mound in a similar situation in Game 6 of last year's NLCS. The Cardinals were up 3-2 in the series, at home and looking to clinch. St. Louis roughed up Kershaw to the tune of seven earned runs on 10 hits over four innings. The Cardinals won, 9-0, and advanced to the World Series.

In Game 1 of this NLDS, Kershaw was staked to a 6-1 lead. He coughed up the whole thing, allowing eight earned runs on eight hits over 6.2 innings pitched. The Cardinals rallied to win, 10-9.

In Kershaw's last two playoff starts, he's allowed 15 earned runs on 18 hits over 10.2 innings pitched. Those aren't numbers you would associate with someone whose name is being mentioned alongside some of the all-time greats.

Most experts picked the Dodgers to win this series, because they figured the combination of Kershaw and teammate Zack Greinke would be too much for the Cardinals to handle. Greinke did his part in Game 2, a 3-2 Dodgers victory, and he's poised to pitch Game 5 back in Los Angeles if Kershaw can lead the Dodgers to a win in Game 4.

This game is a defining moment for Kershaw. His postseason failures are a black mark on an otherwise brilliant resume. As of this writing, we're just three hours from the first pitch of Game 4. I'll be interested to see how Kershaw responds in this pressure-packed start.

Francisco Liriano pitches Pittsburgh Pirates into NLDS

Coming into this year, the Pittsburgh Pirates hadn't had a winning season since 1992. I don't think too many people picked the Pirates to go to the playoffs back in April, but here they are, still playing as the calendar turns to October. They went 94-68, and they are one of the feel-good stories of the year.

Pittsburgh will head to St. Louis to open the National League Division Series on Thursday night after its 6-2 victory over the Cincinnati Reds in Tuesday's NL Wild Card Game.

How does a team like the Pirates go from the outhouse to the penthouse so quickly? Well, like everything else, it's a combination of skill and luck. You need some guys to come out of the woodwork and have surprise years for you. Take Francisco Liriano (pictured), for instance.

By any standard, Liriano had a lousy 2012. He went 3-10 with a 5.31 ERA in 22 starts with the Minnesota Twins. He was traded to the White Sox midseason, where he failed to make an impact. In 12 appearances (11 starts) on the South Side, he went 3-2 with a 5.40 ERA. Manager Robin Ventura could not trust Liriano in big games, and the left-hander was one of the reasons the Sox spit up their AL Central lead late in the season.

Liriano became a free agent and had few offers over the offseason. The Pirates took a chance, and it has paid huge dividends. Liriano made 26 regular season starts for Pittsburgh and won 16 of them, finishing 16-8 with a 3.02 ERA. It was easily his best season in three years.

He found himself on the mound Tuesday night against Cincinnati, and he delivered perhaps the most clutch performance of his career. He went seven innings, and he allowed just a run on four hits while striking out five. Much like the Pirates as a team, Liriano has gone from the scrap heap to relevance in just one year.

The win was Pittsburgh's first in the postseason since Oct. 13, 1992. That has to be a good feeling for Pirates fans. They'll be underdogs against the mighty Cardinals for sure, but they've waited a long time for playoff baseball in that city. They have the opportunity, in part, because they've gotten surprising contributions from guys like Liriano.