For the first time since 2012, the Celtics have a question mark at the shooting guard spot. The significance of losing Avery Bradley cannot be understated. The 27-year-old shooting guard was a foundational piece for Boston's system, who settled into a defined role of locking down the best opposing guards and contributing off-ball versatility on offense. In Boston, Bradley complimented Isaiah Thomas seamlessly on both sides of the floor. In identifying his replacement, Brad Stevens needs a player who insures against Thomas's defensive issues and who can produce as the fourth offensive option. 

In today's position-less NBA, Gordon Hayward has the ability to move from small forward to shooting guard. Until 2013, he played the majority of his minutes in Utah at the 2. Hayward and Isaiah Thomas would be one of the most formidable offensive backcourts in the NBA. Most teams don't have the multiple perimeter defenders to handle elite scoring backcourt duos. Boston's opponents would need to pick their poison with who to prioritize defensively. The backcourts in Washington, Portland, Toronto, and Golden State capitalize on this all the time. When one scorer is blanketed, the other has the freedom to take over. Hayward and Thomas are both capable of running an offense and creating their own shot. In theory, Boston could roll out a trio of Hayward, Jae Crowder, and Marcus Morris. Such a lineup with three switchable wing players with Thomas and Horford would offer interchangeable positional schemes. Filling the roster with an excess of multi-purpose wings is the epitome of modernized basketball philosophy, and it's easy to see how the forward thinking Celtics could be sold on that level of versatility. 

The Celtics reportedly love Hayward's multi-faceted defensive skills. Over his seven seasons, he's has added muscle to help hold up against post players, yet he's maintained the quickness to chase guards off-ball. His 7'0" wingspan offers him significant mismatch length when trying to disrupt opposing shooters. At 6'8", he would be one of the bigger shooting guards in the NBA and would provide balance playing next to Thomas. Per NBA.com, Hayward had a contested defensive field goal percentage of 33.1% on 3s, a few ticks better than the 35.8% league average. Despite Bradley's defensive genius, there were times when the 6'2" shooting guard was exposed for his lack of height. Hayward would not have those problems.  Bradley is undoubtedly the more heralded defender overall, but Hayward is more switchable from a positional matchup perspective. 

The question is whether Hayward's perimeter defense will hold up next to Isaiah Thomas, whose own defensive limitations are well documented. By starting Hayward, the Celtics will no longer have the luxury of throwing a high caliber defender at the opposing best guard. Hayward's 102.0 defensive rating last season was better than Jaylen Brown (105.1) and Marcus Smart (104.5), but he accomplished those numbers locking down mostly wings. not shooting guards. If Hayward has to defend smaller players, he'll be best trying to use his length to bother craftier guards like DeMar DeRozan. Hayward isn't quick enough to stay in front of the speedier likes of John Wall, Kemba Walker, or Kyrie Irving. In order for Hayward to work in at the 2 guard full-time, he has to survive defensively in the bad matchups. 

Marcus Smart is the closest thing that Boston has to mimic Avery Bradley's role. He's a defensive stopper who can switch 1-3 and onto small ball 4s, a range even wider than Bradley's. Smart doesn't have Bradley's shuffling speed, but his bulldog-like tenacity and strength make him the better all-purpose defender. If Thomas' defense has already reached its ceiling, then Smart is the most logical choice. For opposing guards, trying to generate offense against Smart is exhausting. He plays with a physicality that makes it hard for opposing guards to get into offensive sets. The NBA's point guard talent pool has never been greater, and it's difficult to compete for a championship without having a defensive stopper in the backcourt. Just look at the variety of players that Smart defends in this highlight video. 

Smart's offensive fit with the starters is a bit perplexing to me. He's at his best with the ball in his hands getting downhill with the option to kick to shooters or rim runners. He's settled into his role as second unit quarterback. He's improving as a pick and roll player, and his court vision is underrated. Smart's usage rate has climbed each year. It would be a shame to see him playing off ball more. Terry Rozier isn't ready to assume the backup point guard role yet. 

Marcus's impact may be simply too valuable to remove him from the sixth man role. His energy off the bench is demoralizing for fatigued starters midway through the first and third quarters. Smart's ball offense has a long way to go before he can become a formidable floor spacer. Taking Smart off the ball would run counter to how the Celtics have been trying to develop him for three years. I see him as a ball dominant point guard because that's the way Brad Stevens uses him. Per NBA.com, Smart and Hayward were in the 88th percentile in touches per game. Thomas was in the 98th percentile. Al Horford was in the 95th percentile amongst centers. Having Boston's four best facilitators on the floor may not be the wisest allocation of ball handling resources. 

Starting Jaylen Brown is the outside-of-the-box thinking option. When Bradley was sidelined by a January Achilles injury, Brown saw an increase in meaningful playing time. In spot 12 starts, he averaged 9.5 points and 4.3 rebounds in just 24.5 minutes per game and the Celtics won 10 of 12 without Bradley. The Celtics have remained loyal to their two pronged goals of trying to compete for now and beyond the Hayward/Thomas/Horford era. Tapping Brown to start would be a big development toward the latter. He could square off with the league's best guards in the minutes when everyone has their freshest legs. 

The 6'6" combo wing has enormous defensive upside, and according to MassLive's Jay King, Brad Stevens has already informed Brown that he will be tasked with defending quicker guards moving forward. The benefit of starting Brown is that he can focus solely on the defensive end. As the 4th or 5th option in the starting offense, Brown would largely benefit from teammates creating open shots for him. Bradley blossomed into a defensive stopper after being input into the starting lineup in 2013, and the doing the same could kick start Brown's progress. From a developmental viewpoint, Brown is prepared to take on more responsibility in his second season. Perhaps a narrowly focused role as a defensive stopper is the best way to cultivate the promising sophomore. 

Brown's inconsistent jump shot is the biggest thing keeping him from being a starter. He dominated summer league, proving that his one-on-one scoring has improved. However, Brown's role would be vastly different in the Celtics starting lineup. Like Smart, he would be used as a spot up shooter, as a cutter, or as a line filler in fast breaks. Per NBA.com, Brown converted 36.6% on catch and shoot attempts last season. Bradley was at 39%. Stretching the defense with floor spacing is an indispensable component for Boston's offense, and Brown has to be able to attract help defenders off of Thomas and Hayward. It's increasingly more important now that the Celtics have replaced floor spacers Jonas Jerebko and Kelly Olynyk with the more traditional Aron Baynes and Ante Zizic. Brown's jump shot dramatically improved in just one calendar year in the Celtics organization, and at only 20 years old, he has more room to grow. 

The choice for starting shooting guard in October could have a rippling effect on the rest of the roster. If it's Hayward, Jae Crowder would be cemented into the small forward spot. In contrast, Hayward could start at the 3, leaving the Celtics with the difficult decision of benching Crowder or starting Horford as a small ball 5. Either choice would represent a dramatic change from last season. If Smart starts, it could mean that isolation specialists Marcus Morris and Jayson Tatum could be asked to help Rozier run the second unit. If it's Brown, perhaps that forces Marcus Morris into the starting lineup to provide an offensive spark. The theoretical iterations are endless.