The Cubs clinched based on someone losing in 2015, 2016, 2018 and 2020. Only in 2017 did we clinch with a win. I believe in 2015, 2016 and 2018 we had a chance to clinch with a win but lost and relied on help. Hopefully we take the bull by the horns and put this 5 year playoff drought to bed today.
From playoff appearances that I remember:
-1998 - Clinched with win over SFG (Game 163)
-2003 - Clinched with win over PIT
-2007 - Clinched with MIL loss to SD
-2008 - Clinched with win over STL
-2015 - Clinched with SFG loss to OAK
-2016 - Clinched with STL loss to SFG
-2017 - Clinched with win over STL
-2018 - Clinched with STL loss to MIL
-2020 - Clinched with PHI loss to WAS
Edit: Nevermind on 2016, looked it up...the Cubs clinched a playoff berth in 2016 with a win over STL, but they had a chance to clinch the division later on and lost and clinched with an STL loss to SFG