Heading into the 2019 Overwatch League Finals, most experts favored the San Francisco Shock to win the championship. That said, the Vancouver Titans weren't expected to be an easy opponent by any means—after all, the Titans, and not the Shock, were the only team to not lose a match during the postseason. That's why, even though the Shock were the favorites to win, the final 4-0 scoreline proved that not only are Shock currently the strongest team in all of Overwatch, but that it could be fair to say they've secured that position by a significant margin.
Subbing In At The Right Time
Any analysis of what makes the Shock so formidable starts, of course, with its players. Not only is there not a weak link in their starting six, but practically any of the 10 players on the roster could be an all-star. That's why when the Shock fielded bench players Nevix and Super in Map 4 of their playoffs match against London (and won), the look wasn't so much that of a "B team" but what could be a legitimate championship-contending roster in an alternate Smurf-less, Choihyobin-less universe.
This allows for map-specific substitutions, of which the Shock took full advantage, fielding DPS duos of Striker/Sinatraa and Architect/Rascal on alternating maps during the finals. Rascal's eleventh hour Pharah switch during their last attack on Eichenwalde is perhaps the foremost example of why these switches work. Simply put, Rascal is a god on Pharah, and by not having to spread his attention across the entire map pool, he can focus solely on Pharah on maps in which she works particularly well and make these sorts of big plays.
A Strong Coaching Staff
A significant share of the credit is also naturally due to coach Crusty and the rest of the Shock's coaching staff. From leading the Boston Uprising in their nearly-perfect stage during the inaugural Overwatch League season to the Shock not dropping a single map after their loss to Atlanta in the postseason, Crusty seems to know some things that the other Overwatch League coaches don't, and takes full advantage of his advanced insight, from his ample use of the team's full roster, to subtler things like however he helped coach Sinatraa and Super from middling Inaugural Season players to 2019 Season all-stars.
That said, it's the Shock's consistency above all else that the Titans couldn't match. While Vancouver is as capable of big plays as any of them (see Haksal's Meteor Strike in round one of Lijiang Tower), at their worst, the Titans are worse than the Shock at their worst. This is significant, since winning top level team fights in Overwatch often means taking advantage of one small mistake and snowballing from there. The Shock just don't make mistakes, and on the off-chance that they do and lose a fight, they more often than not bounce back with another round of near-flawless play. That's why every step Vancouver took forward was accompanied by another two back—they would inevitably slip up before the Shock would, which is just the sort of perfection-minded gameplay, possible due to the Shock's stacked lineup and coaching, that was reflected in the final 4-0 scoreline.