CBS (and most major US broadcast networks like NBC) use 1080i (interlaced) for NFL games and other live programming primarily due to legacy infrastructure decisions made during the transition to high-definition TV in the late 1990s and early 2000s, combined with bandwidth constraints in over-the-air (ATSC 1.0) and cable/satellite distribution. Historical and Technical Reasons
- When HD standards were set, broadcasters had to choose between 1080i (higher resolution: 1920x1080 lines but interlaced—sending odd lines then even lines alternately, effectively 30 full frames per second) and 720p (lower resolution: 1280x720 lines, but progressive—full frames at 60 per second).
- Networks like CBS and NBC picked 1080i because it provided superior detail for static or slower-moving content (e.g., scripted shows, news, studio programming), which made up much of their lineup at the time.
- Fox and ABC/ESPN chose 720p because progressive scan handles fast motion better (less artifacts like combing or blur in sports), which suited their heavier sports focus.
- 1080p60 (full 1920x1080 progressive at 60 fps) was not practical then—it would require roughly double the bandwidth of 1080i or 720p, and equipment/transmitters were expensive and not widely supported.
Bandwidth and Distribution Constraints
- US over-the-air broadcast (ATSC 1.0 standard) limits channels to about 19 Mbps per station. 1080i and 720p fit efficiently within this (using MPEG-2 compression), allowing room for subchannels (e.g., weather, retro TV).
- Switching to 1080p would demand more bitrate for the same quality, potentially requiring advanced compression (like H.264/HEVC) that older systems don't fully support, or reducing other channels.
- Cable/satellite providers and local affiliates inherit the network feed, so they transmit in 1080i too. Even modern productions often capture in 1080p HDR internally but down convert to 1080i for broadcast transmission.
Current Status (as of 2026)
- Production has evolved: CBS now captures most NFL games in 1080p HDR (with more cameras and better quality), but transmission remains 1080i to maintain compatibility and bandwidth efficiency.
- Streaming on Paramount+ simulcasts the broadcast feed, so it's typically 1080p (deinterlaced/upscaled from the 1080i source), but not native higher than that for live games.
- True 1080p or 4K broadcast is emerging slowly via ATSC 3.0 (NextGen TV) in some markets, but adoption is limited, and CBS hasn't widely used it for regular NFL games.
In short, it's a mix of historical lock-in (expensive to overhaul nationwide infrastructure) and practical efficiency (1080i delivers good quality within existing limits). Modern TVs deinterlace 1080i excellently, so the difference from native 1080p is often minimal for most viewers—especially compared to compression artifacts or bitrate issues.