There are no real surprise teams in the playoffs. Sure, it was a surprise that a 16 year-old New Zealand girl wrote a song about George Brett that became a number one hit and a sort-of mantra for Kansas City's marketing strategy. But it wasn't really a surprise that the Royals made the playoffs -- they only missed by a handful of games in 2013.
Instead, we find these divisional series filled with returnees (Dodgers, Cardinals, Tigers) and clubs who underperformed in 2013, only to regress to their inevitable mean (Natitude!) in 2014. To call the Giants and Nationals "better" in 2014 is a given: the teams improved by 12 and 10 wins, respectively. But these two squads merely improved cosmetically -- supplementing pieces here and there -- the real work was done within.
2013 San Francisco Giants: 76-86, 3rd NL West
2014 San Francisco Giants: 88-74, 2nd NL West, Wild Card
Lost: Marco Scutaro (injured)
Gained: Joe Panik
Better or worse? The Giants lost Scutaro, who was old, and Zito, who was old and also bad. The club did add Tim Hudson (also old!) at the offseason drive-thru window, and swung a highly-effective midseason trade for Jake Peavy (which became necessary after a season-ending injury to Matt Cain). The bullpen has been up and down, highlighted by Yusmeiro Petit, Santiago Casilla, and Jeremy Affeldt. Madison Bumgarner has been Madison Bumgarnerian. Overall, the Giants have lowered their team ERA from 4.00 to 3.50, and went from 12th in the league in walks to 2nd (although they also went from 4th in K's to 13th -- *cough* TIm Hudson! *cough*). The San Francisco lineup is nearly identical to 2013, though Buster Posey has added seven home runs, 17 batting average points, and 33 OPS integers. Pablo Sandoval has had nearly the exact same season as 2013 (.278/.341/.417, 14 HRs in 2013; .279/.324/.415, 16 HRs in 2014), and Hunter Pence has mostly hit well despite scuffling down the stretch. Mike Morse was a fantastic addition early, but has missed huge stretches in the second half.
The Giants? Better with age.
2013 Washington Nationals: 86-76, 2nd NL East
2014 Washington Nationals: 96-66, 1st NL East
Lost: Kurt Suzuki
Gained: Asdrubal Cabrera
Better or worse? The Nats didn't jettison a single everyday player from last season, with the exception of fourth starter Dan Haren, whose FIP (4.09) was higher than every other National who tossed over 28 innings. The team traded for Doug Fister as a replacement, who now leads all Washington starters with a 2.41 ERA. Tanner Roark, a bullpen tosser in '13, has emerged (2.85 ERA, 1.09 WHIP), and Stephen Strasburg has kicked his K/BB up from 3.41 to 5.63. Jordan Zimmerman's K/BB has similarly risen -- from 4.03 to a team-leading 6.28. The Nats have been without Ryan Zimmerman much of the year, but his absence has been muted by Anthony Rendon's presence, as Rendon easily leads the team in WAR (6.5). Denard Span has improved (from .279/.327/.380 to .302/.355/.416), Adam LaRoche too (from .237/.332/.403 to .259/.362/.455). The team even brought in Asdrubal Cabrera (just two years removed from being an All Star, and three years removed from hitting 25 bombs) to play second.
The Nats? Wholesale improvement.