Time plays cruel jokes on each side in different phases of a round. Professional players use time in their favor. Often, you can see combinations of terrorists rushes to the respective bomb sites in timings as late as 20 seconds before the end of a round. To do this effectively, they prepare accordingly and try to stretch their opponents out and deceive them by faking different sites.
In these 20 seconds, it is very important to kill 1-2 CT players and still have time to plant the bomb. When making these dangerous timings work, always remember the time required for planting the bomb.
Before the bomb is planted, the time is working in favor of the CT team, but after it is planted, the CT team has only 40 seconds to defuse the bomb.
At such moments, it is important to have at least 1-2 defuse kits per team. As practice proves, the five-second difference gives a colossal advantage.