MGM Resorts (MGM 0.98%) reported fourth-quarter results on Thursday, and the numbers did nothing to please investors. Shares dropped as much as 9% in Friday trading as Macau results disappointed and the opening of MGM Cotai was pushed back.

Overall, revenue was down 8.1% in the fourth quarter to $2.19 billion, and net loss more than doubled to $781.5 million, or $1.38 per share. The large loss was mostly due to a $1.5 billion writedown of MGM China, which is 51% owned by MGM Resorts. But the details within those numbers are what's worth watching.

The skinny on Las Vegas
Long term, Las Vegas is becoming far less dependent on gaming than it's ever been before, and that continued in 2015. During the fourth quarter, casino revenue from wholly owned domestic resorts fell 5%, but overall revenue was up 2%. Room revenue growth of 10% was a big driver of growth.  

Adjusted EBITDA, a proxy for cash flow from a resort, jumped 15% to $430.7 million for these wholly owned domestic resorts. That's great improvement from a financial standpoint and is the most important figure investors should look at.

This slow and steady performance in Las Vegas has become the norm among gaming operators, and it has helped MGM Resorts remain stable while Macau-focused competitors faltered.

CityCenter finally holding its own
The massive CityCenter resort is also in Las Vegas, but it isn't consolidated because MGM only owns half of the resort. And after years of struggling to justify its $9+ billion price tag, it is now starting to perform mildly well.

Revenue from operations increased 12% in the fourth quarter to $323 million, and operating income was $19.3 million versus a loss of $18.1 million a year ago. Aria was the star in the quarter, increasing revenue per available room 7% to $212 and seeing table game volume jump 12%.

While Las Vegas was steady and CityCenter improved, MGM China struggled along with the rest of the industry.

MGM Cotai is delayed
It's no surprise that MGM China's results were down. Macau's gaming revenue overall was down 27.5% in the fourth quarter; the problem is that MGM underperformed the market.

MGM China's revenue fell 31% to $499 million in the fourth quarter, and adjusted EBITDA dropped 29% to $131 million -- both worse than the market as a whole. But it was a 57% drop in VIP table game turnover that was a real shocker to investors.

The weakness in Macau is a concern, but MGM China has always been able to look forward to MGM Cotai, its first move to the lucrative Cotai region. However, the company announced it would delay the project from a fourth-quarter 2016 opening to an opening near the end of the first quarter of 2017.

This makes some sense given Wynn Palace opening this summer and then Las Vegas Sands' The Parisian opening near the end of the year. The issue is that MGM Cotai needs to start generating revenue as soon as possible to pay for its $3.0 billion construction cost. A delay is a huge disappointment for the company.

The good and bad of MGM Resorts
Las Vegas continues to be the rock-solid foundation of MGM Resorts, and its slow improvement continues. But Macau operations were even worse than anyone expected, and the company lost market share. Until the opening of MGM Cotai and the cash flow that will come from that resort, this is a slow-growth, domestic-focused company, for better or worse.