The primary disadvantage of 30-20-10 became an advantage when applied to the team game: the slower pace made the questions possible to discuss. Now the pause in between questions had a function: it was a time for team members to put their heads together and come up with the best possible answer. This became what is now the bonus.
The bonus went through a lot of phases, but it eventually settled into its modern incarnation: a question split into 3 related parts that are worth 10 points each. Notably, the parts are all worth equal value and no order is formally assigned. This was primarily done to make things easier, as it is far more convenient to add up points when you don't have to remember what the easy, medium, and hard parts were. It also makes question writing more flexible; when you don't have to go in the same hard-medium-easy order all the time, you have more freedom to tell the story you want to tell.
This relates to the secondary function of bonuses: to explain. Tossups are inherently difficult to understand at game speed: when the information is whizzing by and dancing around the topic at hand, it is hard to figure out what is happening unless you're already familiar with the subject. However, bonuses are much easier to follow and often use an instructional tone; they explain to the player exactly what they are asking for and why that thing is important. In this way, they are a much more beginner-friendly introduction to the game than tossups. Bonuses are often used by novice players to improve when they are first starting out.
In order to illustrate how bonuses relate to tossups, here is an example of a bonus and a tossup on the same subject:
[10] Name this poem concerning the title resident of Tilbury Town, a “child of scorn” who was “born too late” and mourned “Romance” and “Art.”
ANSWER: “Miniver Cheevy”
[10] This poet of “Miniver Cheevy” also wrote of a “gentleman from sole to crown” who “one calm summer night / went home and put a bullet through his head,” Richard Cory.
ANSWER: Edward Arlington Robinson
[10] Climbing a hill and drinking out of a jug, this other resident of Tilbury Town sings “For auld lang syne” to himself “amid the silver loneliness / of night” in his title poem, which describes the town.
ANSWER: Eben Flood (accept Mr. Flood or “Mr. Flood’s Party”) [Yue, 2021 PACE NSC]
ANSWER: Edward Arlington Robinson [2018 Harvard Fall Tournament]
The content of these two question is mostly the same, with the answers to each of the three bonus parts appearing in the corresponding tossup. But these questions play very differently. Teams usually spend 5-10 seconds conferring on each bonus part, depending on the rules. This slows the game down, allowing players to somewhat rest their brain between tossups. Since each bonus part is worth 10 points (for a total of 30 points), they make up the bulk of the points. However, tossups generally still decide the match as bonuses are generally only awarded to the team that answered the last tossup.
The tossup and the bonus complement each other and form the two halves of the modern quizbowl game. Now that we've seen the origins of tossups and bonuses, let's see how they all come together in Part IV: Gameplay.