How to implement lottery in Delphi7?

Question

Delphi

Good day, comrades!
I state: there is a database on MS SQL Server 2012 and a program for holding a martial arts competition, including the following sections:
1) Registration of participants - here athletes are entered into the database with certain attributes;
2) Obtaining information - is a set of requests for data from the 1st section;
3) Draw- there are comboboxes for setting category attributes (gender, age, weight) and as a result, a list of athletes corresponding to the above category attributes is displayed in DBGrid (For example, husband, 18+ years old, up to 78 kg), as well as the place where the result query from the table, participants are entered in pairs and all this is saved for provision to the next section on demand;
4) Competitive mode - should, at the choice of category, show the result of the draw, according to which athletes are already invited in pairs to conduct a duel.
Problem - I can not decide on the choice of the algorithm for the draw. That is, displaying a list of athletes that satisfies the attributes of the category is obtained without problems, butyou need to somehow separate them into pairs, make the tournament bracket in this way, and save for use in the next section

Answer 1

pure random.
Well, there is also the so-called sowing.
That is, let's say 4 people out of 32 are potentially stronger than the rest. "Sow" them. That is, 8 to 1. So that they would not meet before the semi-finals.