A thousand attendees, and a delegation of thirty
The Association for Talent Development brings its OrgDev conference to the Indiana Convention Center on September 29 to October 1, 2026. The venue's event listing carries a forecast attendance of 1,000 and places the programme in Sagamore 1-7. ATD describes OrgDev as a conference for organization development programmes, with sessions on culture, talent strategy and management, leadership and employee development, and human resources.
The venue page displays a second date line of September 30 to October 1 for the same programme, so confirm the start date with the organiser. Your delegation is a fraction of the 1,000. Fifteen to forty rooms is the range this piece covers.
Fifteen to forty rooms sits inside the group definition
groupRooms.org defines a group rate as a discounted rate for a block of 10 or more rooms. A delegation of this size clears that threshold. Four terms decide the outcome: the room-night count you commit, the attrition floor, the cutoff date and the rate.
Turn rooms into room nights
Thirty rooms across three nights commits 90 room nights. An 80 percent floor sets the obligation at 72. Every room night below 72 bills at the contracted rate, and Blocks, a room-block software vendor, reports that a negotiated lost-profit clause can price the shortfall at roughly 75 percent of the rate.
Do the multiplication before you sign. Fifteen rooms over three nights commits 45 room nights and an 80 percent floor of 36. Forty rooms over three nights commits 120 room nights and a floor of 96. Fifteen rooms over four nights commits 60 room nights and a floor of 48.
Count the shortfall night by night
Blocks measures attrition floors per night in its worked examples. Take thirty rooms across three nights with an 80 percent floor, which sets a floor of 24 rooms each night. Fill the middle night at 30 and leave both shoulders at 20. The block total reads 70 against an obligation of 72, two room nights short. The per-night view reads eight room nights short, four on each shoulder. At the guide's illustrative $189 rate that is $1,512 against $378.
The small block carries the same per-night exposure as a large one. The rate in that comparison is the vendor's own illustration, and the arithmetic is the part to copy into your own numbers.
Set the cutoff as a calendar date
Blocks reports cutoff dates commonly landing about 30 days before arrival, flexing between 21 and 30 days, and reaching 45 days out in peak season. Its guide recommends a specific calendar date in the contract.
A September 29 arrival puts a 30-day cutoff at the end of August. Indianapolis carries concurrent demand that week. The venue's own event feed lists ATD Core4, MAPP and ATD OrgDev all running September 29 to October 1, and the 12,000-attendee Do it Best Corp. Fall Market checks out on September 28.
Four nights when the delegation flies in
The programme opens Tuesday September 29 and closes Thursday October 1. A delegation that lands Monday September 28 and flies out Friday October 2 needs the nights of September 28, 29, 30 and October 1. A delegation that leaves Thursday evening needs three nights. That fourth night sits on a shoulder, and the hotel's floor applies to it.
Indianapolis inventory in the same window
Downtown Indianapolis holds 7,100 hotel rooms. The venue reports that more than half sit within blocks of the convention center and Lucas Oil Stadium, and that 4,700 rooms connect to the venue by skywalk. The venue also reports 200 downtown restaurants within walking distance and 15 minutes to the airport. The skywalks lock down at about 11:00 p.m. and reopen at about 6:00 a.m., and the venue states the timing is event-dependent.
groupRooms.org lists 273 hotels in its Indianapolis directory, so alternative houses exist when the walkable core tightens around the three conferences.
What to negotiate, and what to ask for
Blocks names a low pickup floor, a resell credit and force majeure protection as the three items to settle before signing. Add the questions a small block raises. Ask how the hotel measures the floor and whether that measurement runs per night. Ask what its comparable training groups have taken. Ask what happens to unreserved rooms after the cutoff and whether the group rate survives the cutoff date.
No source publishes the pickup curve for this programme. Ask the hotel for its own comparable data.
Compare Indianapolis block rates on groupRooms.org
groupRooms.org publishes 103,857-plus hotels across 46 states, 50-plus hotels per request, a 24-to-72-hour response window, $0 fees and contract-ready proposals for bookings of 10 or more rooms. The same page states that a few states (FL, HI, IA, WA) restrict group hotel bookings under state travel laws. Indiana sits outside that list.
Submit the delegation's dates, its room count and the nights that matter. Hotels bid against each other. Compare the offers on the all-in room night and on the per-night floor each one writes into the contract.
