By winning the 2017 Australian Open final against her sister Venus Williams, Serena Williams secured which Grand Slam singles title number of her career?

Introduction / Context:
Serena Williams is one of the greatest tennis players in history, with an outstanding record in Grand Slam singles tournaments. In 2017, she faced her sister Venus Williams in the Australian Open final and won the title. This victory pushed her past many previous records and is widely discussed in tennis history. The question focuses on the total number of Grand Slam singles titles Serena had after winning that final.

Given Data / Assumptions:

• The tournament is the 2017 Australian Open.
• The final was played between Serena Williams and Venus Williams.
• Serena Williams won that final.
• We must identify which numbered Grand Slam singles title (e.g., 23rd) this victory represented for Serena.

Concept / Approach:
By January 2017, Serena Williams had already accumulated an impressive collection of Grand Slam singles trophies. Her win over Venus in the 2017 Australian Open final brought her total to 23 Grand Slam singles titles, breaking the Open Era record previously held by Steffi Graf (22). It is important to note that we are counting only singles titles, not doubles or mixed doubles, and that the number refers to her career total up to and including that final.

Step-by-Step Solution:
Step 1: Recall that Serena Williams entered the 2017 Australian Open with 22 Grand Slam singles titles. Step 2: Recognize that by winning the final against Venus Williams, she added one more singles title to her tally. Step 3: Calculate the new total: 22 + 1 = 23 Grand Slam singles titles. Step 4: Remember that sports media widely reported she had broken Steffi Graf's Open Era record of 22 singles majors. Step 5: Compare this figure with the options: 23rd, 18th, 26th, and 20th. Step 6: Select 23rd as the correct answer.

Verification / Alternative check:
Official Grand Slam records, tennis statistics databases, and major sports news outlets all state that Serena Williams' 2017 Australian Open victory was her 23rd Grand Slam singles title. They often highlight that this win allowed her to surpass Steffi Graf's Open Era record. None of these sources mention 18, 20, or 26 titles in connection with this particular match, which confirms that 23rd is the correct number.

Why Other Options Are Wrong:
18th and 20th refer to lower totals that Serena had already surpassed earlier in her career and are not associated with the 2017 Australian Open. The 26th title would imply she already had 25 before that match, which is not supported by official records. Thus, 18th, 20th, and 26th are inconsistent with Serena's actual Grand Slam singles tally at that time, leaving 23rd as the only accurate option.

Common Pitfalls:
Some candidates may confuse Serena Williams' singles titles with combined singles and doubles majors, leading to numerical errors. Others may recall that she was chasing a record but misremember the exact number, mixing up 22 and 23. To avoid such mistakes, it helps to note that the 2017 Australian Open was widely publicized as the event where she set the new Open Era record at 23 Grand Slam singles titles.

Final Answer:
By winning the 2017 Australian Open final against Venus Williams, Serena Williams secured the 23rd Grand Slam singles title of her career.