Wowza Media Systems said in a report today that live mobile sports apps are lagging when it comes to presenting simultaneous broadcasts for real-time sports apps to viewers. And Wowza has ranked just how fast some of those apps are.

As in so many other markets like games, video livestreams are transforming the way people watch sports, Wowza said. With the massive audiences attracted by events such as the Super Bowl, World Cup and Olympics, livestreaming sports apps tend to have higher latency, or delays, than user-generated content or gaming apps. The delay on mobile devices is often around 90 seconds, and the result is that those watching on mobile often get hit with spoilers from fans who are watching in real-time.

The results show that Fox Sports Go has significant latency, or delays, in livestreaming, while apps such as WatchESPN and NCAA March Madness have some of the lowest latencies.

Wowza said that when millions of fans are trying to access a single stream concurrently, latency is often injected to allow content delivery networks (CDNs) to cache content—thereby delivering the same high-quality stream to users on a wide variety of devices and operating systems, with different connections and bandwidth.

In Wowza’s testing, most of the desktop browsers defaulted to use the Adobe Flash player. Thus, latency scores across the board were lower when testing the same apps on a desktop computer than when testing on a mobile device.

The bigger trend behind livestreaming

In the past, the only way to catch a big game was to tune in on network TV; for smaller events, cable or satellite television was necessary.

But a growing number of Americans are “cutting the cord” and bypassing traditional television. About 24 percent of Americans don’t have a cable or satellite TV subscription, and 15 percent have cancelled a former subscription. The numbers are even higher for young Millennials: 16 percent have never had a subscription, while 19 percent no longer have one. What’s more, 64 percent of cord-cutting Millennials say they don’t have a subscription because they can access the content they want online.

Major TV companies such as ESPN, Fox and NBC offer livestreaming sports apps, which viewers can use on their smartphones or computers. Major professional leagues, such as the NBA and MLB, are also creating apps.

However, many associations are still keeping a close hold on their digital distribution rights, blocking certain games in specific regions with “blackout” availability.

The 2017 Super Bowl broke records for livestreaming viewership through the Fox Sports Go app. Akamai predicts 500 million viewers will soon be watching livestreamed primetime sports online.

Most sports apps allow viewers to not only watch games in real time, but also to access in-game highlights, past player videos, statistics, fan shops and a host of other built-in elements. Some allow fans to participate in fantasy sports competitions with other users, and get real-time updates on scores, news and statistics from across the league.

Desktop versus mobile livestreaming

Above: Wowza shows how much latency builds over time with livestreamed mobile sports apps. For the March Madness app, the video playback seemed to slow down as the game progressed. During the NCAA March Madness tournament, our teams tested the entire length of four games.

Image Credit: Wowza

Latency is higher on mobile devices versus desktop computers. Desktop browsers have traditionally used the RTMP protocol with the Adobe Flash player plugin, which delivers low-latency streams. However, some browsers—such as Google’s Chrome and Apple’s Safari—are beginning to eliminate support for Flash. Browsers without Flash are best supported by HTML5 players, which can be used in any mobile or Web browser.

For mobile devices, more broadcasters and applications leverage the HLS protocol—which, without fine-grained adjustments, comes with greater latency. HLS requires a significant amount of data to be stored before playback can begin; platforms using a CDN to deliver streaming video will experience additional latency injections. This results in livestreams being delivered to some viewers with latency of up to 90 seconds.

While the goal for broadcasters is to deliver the same experience to everyone, regardless of device, this often isn’t the reality. Because streams must be delivered in diverse formats to devices with a variety of playback and distribution methods, viewers often have different experiences based on the type of device they’re using.

Cable broadcasts tend to have five to 10 seconds of end-to-end latency, and satellite may be as high as 15 seconds. However, the live-streaming sports apps we tested have average end-to-end latency scores ranging from nine to 101 seconds.

The apps in Wowza’s test did have lower time-to-first-frame (TTFF, or the time it takes for a stream to start playing video) scores, starting at two seconds.

Yet another threat to network-backed apps is Facebook’s entry into the live-streaming sports market. The social-networking giant recently made a deal to broadcast 22 Major League Soccer matches from its Facebook Live platform, and is negotiating with MLB to live-stream one weekly game throughout the 2017 season. Thanks to a deal with Univision, Facebook will also live-stream 46 Mexican soccer league games in English.

The results

Above: The first vertical bar graph shows the average Time to First Frame (how long it takes to load the video), and end-to-end latency (the time difference between standard TV and app playback). Here, you can see that While Fox Sports is the fastest to load on desktop, it’s over a minute and a half behind the standard broadcast signal. However, WatchESPN and NCAA March Madness perform the fastest for desktop viewers.

Image Credit: Wowza

NCAA March Madness Live and WatchESPN provide the lowest desktop latency in Wowza’s testing. However, March Madness experiences latency buildups over time, starting at around  three seconds TTFF on a desktop to as high as 48 seconds on mobile in terms of end-to-end latency. MLB At Bat scores with the fastest TTFF and end-to-end latency delivery on mobile devices.

Higher latencies are necessary to maintain quality for large numbers of concurrent viewers, such as the Super Bowl, World Cup and Olympics.

The official streaming app of Major League Baseball was the fastest-performing mobile app in the testing, though its desktop scores are on the high end. On mobile, end-to-end latency was as low as 23 and as high as 34 seconds, with two to four seconds in TTFF. On desktop, end-to-end latency is as low as 32 and as high as 63 seconds; TTFF ranges from two to eight seconds.

FOX Sports Go has the highest latency of the livestreaming sports apps Wowza tested. On both desktop and mobile, end-to-end latency ranged from a minute and a half to nearly two minutes (87 to 110 seconds on desktop; 81 to 107 seconds on mobile). TTFF is lower: two to three seconds on desktop, and five to six seconds on mobile. A cable or satellite subscription is required to livestream games.

WatchESPN and NCAA March Madness Live are neck-and-neck in providing the lowest-latency desktop streams. NCAA March Madness Live has the fastest desktop scores, but provides limited coverage, and suffers from latency buildups over time. WatchESPN has slightly higher desktop latency, but supports interactive extras and a wide range of programming well-suited to sports junkies.