Yes, is that 300 spots (in CS in Engineering? All?)? If so, the acceptance rate would be in the teens (lower for CS in Engineering; higher for CS+X).
@PurpleTitan I believe it is 300 spots for both CS in CoE and in LAS - that’s what it said in the email
OK, @UATenista, slightly fewer than least year, then.
Likely harder to get in.
They admitted far more than 300 students.
Even a super generous assumed yield of 50% would put the admit rate no less than just under 20%.
Professor Pitt’s email did not say anything about number of students admitted. It said…
“Among over 3000 students applying for one of about 300 spots in our freshman class…”*
These numbers encompass the ENG and six LAS majors. I think it is safe to assume that each of the seven majors has its own admit rate, and the range is probably pretty wide. (Professor Erickson disclosed on reddit that about 90% of CS apps were [first choice] to ENG which would put the admit rate there into the mid teens, and the admit rate to the various CS+X majors much higher). I also feel safe in assuming that a great number of ENG applicants listed an LAS CS major as a second choice, which further muddies the math…
…if you double count each rejected ENG major who chose CS+X as a second choice, and they wouldn’t be the first school to do so, then the overall admit rate does get into the low teens, because now you are looking at 5000+ apps.
In the end though, this is all just playing with numbers. Those accepted to CS at Illinois surely are strong applicants elsewhere and have lots of choices. This probably leads to a yield far lower than 50%, and higher admit rates than what I have listed above.
*compare this to CMU, which got 6,800 apps this year for 140 spots. Even CMU is at a sub-40% yield though, so the admit rate will be all the way up over 5%. 
@YZamyatin, pulling from various sources, evidently there were 3300 apps for 330 spots last year and an overall 25% acceptance rate. That would mean a yield of 40%.
It does seem that listing CS+X as a first choice (and maybe as a second choice) to UIUC gives a high stats male kid (who isn’t URM or already coding for money and/or a very advanced coder) the best odds to a top-5 CS program. All the other avenues to a top-5 for such a kid have such low acceptance rates that they’re in lottery territory.
In fact, in the top 15, CS+X@UIUC, UW-Madison (and maybe UMD if you count them) are the only reasonable fairly certain pathways to CS left for someone like I described.
When you look at it that way, the CS+X programs at UIUC are really undervalued. Hidden gems, in a way.
BTW, evidently Stanford is introducing some CS+X majors as well.
Attended the UIUC CS Information Session. For class of 2020, roughly 200 CS students (in Engineering) will attend. Approx 4000 applications were received for CS. They also have an additional 150 CS students from LAS. So, total 350 students out of 4000 applicants will attend. I don’t know to how many students they offered the seats but these numbers represent the expected number of students who will attend.
Anyone know average stats of accepted CS students? Or even engineering?
@thshadow from the UIUC admissions website. http://www.admissions.illinois.edu/Apply/Freshman/profile
summary: Campus middle 50% ACT 27-32,
Engineering middle 50% ACT 31-34.