Predictive / ratio / preview / manual on Vicidial — when each mode fits and what each costs

Vicidial® supports four basic dialer modes per campaign. They trade off the same three variables in different ways: agent idle time, abandon rate, and per-call agent control. Picking wrong is the most common cause of "predictive dialing doesn't work" complaints — the mode was wrong for the campaign, not the platform.

The variables

• Agent idle % — fraction of paid agent time spent waiting for a connected call. Lower is better for operations cost. Predictive dialing exists to drive this toward zero.
• Abandon rate — fraction of answered calls where the prospect hears nothing because no agent was available. Regulated under TCPA (the FCC's 3% rolling 30-day cap for US commercial telemarketing). Lower is always better; the cap is a ceiling not a target.
• Agent control per call — how much info the agent has about the prospect before connecting, and whether they can choose to skip. Preview gives max control; predictive gives none.

Mode 1: Predictive (dial level 1.5-4.0)

Vicidial fires N calls per available agent simultaneously, where N (the "dial level") floats based on observed answer rate. The first call to connect routes to the agent; the rest either get abandoned (with a safe message if you've configured one) or hung up if still in dialing.

Optimizes: agent utilization. Idle approaches zero at steady state with enough call volume.

Costs: abandon rate is the constant tax — the higher you push dial level, the lower the idle but the higher the abandon. The 3% TCPA cap is real money: exceed it and you're in regulatory trouble.

Fits: high-volume B2C with answer rates above 15%. Steady-state operations where the campaign runs for days/weeks with predictable agent count.

Doesn't fit: low answer rate (under 8%) campaigns, where dial level climbs high enough that abandon rate consistently breaches TCPA cap. Switch to ratio.

Mode 2: Ratio (fixed dial multiplier, no auto-adjustment)

Like predictive, but dial level stays fixed at a value you set (e.g., 2.0 calls per agent). Vicidial doesn't autoscale based on answer rate.

Optimizes: predictability — you know exactly how many calls go out per agent, useful for trunk capacity planning and for staying conservatively under TCPA.

Costs: agents will be idle if answer rate spikes high; calls will be abandoned if it spikes low. You're trading the autoscaler for predictability.

Fits: early-campaign tuning when you're learning your answer rate; B2B campaigns where answer rates are volatile; campaigns where you've contractually committed to a maximum abandon rate below TCPA.

Mode 3: Preview

The agent sees the lead's record (name, history, notes, script) for N seconds before the call is dialed, then has to hit a "Dial" or "Skip" button. The call only goes out when the agent commits.

Optimizes: per-call quality, agent preparation, lead-aware conversations.

Costs: agent utilization is terrible compared to predictive. Agent productivity per hour falls significantly.

Fits: high-value B2B sales (one closed deal makes up for 20 agent-hours), warm follow-up calls where the prospect knows the agent's name, regulated verticals (insurance, finance) where the agent needs to record affirmative consent before pitching.

Doesn't fit: cold B2C in any volume.

Mode 4: Manual

Agent dials each number themselves (typing or paste from a sticky note). Vicidial logs the call and records, but does no list management or auto-dialing. Effectively a Vicidial-wrapped softphone with screen-pop.

Optimizes: total agent control, lowest abandon-rate risk (zero by definition).

Costs: the worst utilization of all four modes. You're paying for Vicidial-as-CRM.

Fits: compliance-sensitive inbound followup, collections work where each call is bespoke, lone wolf sales where the salesperson curates their own queue.

Picking and tuning

Start a new campaign in ratio mode with dial level 1.5 for the first day. Watch:

• Answered rate (Real-time main report → Calls Today / Answered Today columns)
• Abandon rate (Real-time main report → DROP%)
• Per-agent idle time (Agents → status timeline)

After 4-8 hours of running, you'll have a baseline answer rate. If it's stable and above 15%, switch to predictive and let Vicidial autoscale. If it's volatile or low, stay in ratio and tune the multiplier manually.

Auto-adjust controls in predictive mode

Campaign config → Dial Level controls:

• Auto Dial Level = ON enables autoscaling.
• Dial Level Target — the desired connected-calls-per-available-agent. 0.95 means "I want agents busy 95% of the time." Lower targets reduce abandon rate but waste agent hours.
• Maximum Adapt Calls Per Second — caps how aggressively dial level changes. Set to 1 or 2 to prevent oscillation when answer rates wobble.
• Drop Call Seconds — how long Vicidial waits for an agent to become available before abandoning an answered call. Should be set to a small number (2-3 seconds is typical) — longer values let prospects hear silence and contribute to abandon impressions even if Vicidial doesn't classify them as abandoned.

Common misconfigurations

• Predictive mode with 2 agents — Vicidial needs statistical headroom to autoscale. With fewer than 5 agents, every connect is a 20% deviation from the scale model; abandon rate swings wildly. Use ratio below 5 agents.
• Ratio mode at 4.0 dial level on a 6% answer rate — abandon rate will be 8-12% sustained. TCPA violation territory. Either lower the dial level or accept that this list quality justifies preview.
• Preview mode with no skip allowed — agents will rush, leading to mistaken calls and complaints. Preview without skip is just slow predictive with extra steps. Always allow skip on preview.