Chelsea began their official pre-season schedule with a 2-1 victory over Championship side AFC Bournemouth, courtesy of second-half goals from Armando Broja and Ike Ugbo.Thomas Tuchel's side fell behind in the 66th minute to an Emiliano Marcondes strike, but soon responded with two goals in rapid succession. A raft of players were brought into the side for Chelsea, but it was the young strike pair that handed them a morale-boosting win.As for the Cherries, Scott Parker's side showed immense promise in some areas of the field. Their full-backs, along with David Brooks, were some of the positive aspects of their narrow defeat.On that note, we list the top five major talking points from Chelsea's pre-season victory at the Vitality.Pre-season begins with a win! 😃— Chelsea FC (@ChelseaFC) July 27, 2021#1 New-look Chelsea start with a back threeDujon Sterling started across the three-man back line for ChelseaThere was a lot of talk about Tuchel's experiments in formations ahead of the new season. The German boss had absolutely no time to assemble a squad structure on the pitch, but despite collective discussions on a back four, he opted to start with Lewis Baker, Dujon Sterling and Malang Sarr.The trio were completely solid in the first-half as they restricted Bournemouth to just one wayward shot on goal.Danny Drinkwater and Conor Gallagher started in a double pivot, with Marcos Alonso and Callum Hudson-Odoi flanking the wing-back positions. Christian Pulisic, Tammy Abraham and Hakim Ziyech formed what was a strong front three.#2 Chelsea grow into the game with the help of widthDanny Drinkwater had a promising first-half for ChelseaFrom the Cherries' perspective, young David Brooks was the liveliest of players owing to his glossy touches, trickery and fearlessness on the right-hand side.Chelsea were on the backfoot in the opening exchanges of the game, but slowly found their groove as the minutes wore on. Their main route of attack was when Danny Drinkwater found space from a deep position and pinged diagonals to Hudson-Odoi.The latter was at his blistering best, running at Bournemouth left-back and crossing with conviction. One of his crosses was met neatly by Abraham, but Mark Travers was equal to it with an outstanding save from point-blank range.Drinkwater also played a lovely through ball to Abraham, who fired in a fierce shot straight at Travers. Another header from the Chelsea number 9 went just over the bar, which portrayed the Blues' threat from crosses.